SEC Info - Gladstone Commercial Corp. - ‘10-K’ for 12/31/22

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Gladstone Commercial Corp. – ‘10-K’ for 12/31/22 – ‘EX-101.LAB’

On: Wednesday, 2/22/23, at 4:06pm ET · For: 12/31/22 · Accession #: 1234006-23-3 · File #: 1-33097

Previous ‘10-K’: ‘10-K’ on 2/15/22 for 12/31/21 · Next & Latest: ‘10-K’ on 2/21/24 for 12/31/23 · 21 References:

  As Of               Filer                 Filing    For·On·As Docs:Size

 2/22/23  Gladstone Commercial Corp.        10-K       12/31/22   82:19M

Annual Report — Form 10-K

Filing Table of Contents

Document/Exhibit                   Description                      Pages   Size 

 1: 10-K        Annual Report                                       HTML   4.51M 
 2: EX-4.6      Instrument Defining the Rights of Security Holders  HTML     88K 
 3: EX-10.12    Material Contract                                   HTML     24K 
 4: EX-21       Subsidiaries List                                   HTML     34K 
 5: EX-23       Consent of Expert or Counsel                        HTML     25K 
10: EX-99.1     Miscellaneous Exhibit                               HTML     25K 
 6: EX-31.1     Certification -- §302 - SOA'02                      HTML     28K 
 7: EX-31.2     Certification -- §302 - SOA'02                      HTML     28K 
 8: EX-32.1     Certification -- §906 - SOA'02                      HTML     25K 
 9: EX-32.2     Certification -- §906 - SOA'02                      HTML     25K 
16: R1          Cover Page                                          HTML     98K 
17: R2          Audit Information                                   HTML     30K 
18: R3          Consolidated Balance Sheets                         HTML    151K 
19: R4          Consolidated Balance Sheets (Parenthetical)         HTML     59K 
20: R5          Consolidated Statements of Operations and           HTML    164K 
                Comprehensive Income                                             
21: R6          Consolidated Statements of Equity                   HTML    122K 
22: R7          Consolidated Statements of Cash Flows               HTML    169K 
23: R8          Organization, Basis of Presentation and             HTML     65K 
                Significant Accounting Policies                                  
24: R9          Related-Party Transactions                          HTML     47K 
25: R10         (Loss) Earnings per Share of Common Stock           HTML     50K 
26: R11         Real Estate and Intangible Assets                   HTML    116K 
27: R12         Real Estate Dispositions, Held for Sale, and        HTML     55K 
                Impairment Charges                                               
28: R13         Mortgage Notes Payable and Credit Facility          HTML    149K 
29: R14         Commitments and Contingencies                       HTML     37K 
30: R15         Equity and Mezzanine Equity                         HTML     98K 
31: R16         Subsequent Events                                   HTML     49K 
32: R17         Schedule III - Real Estate and Accumulated          HTML    663K 
                Depreciation                                                     
33: R18         Organization, Basis of Presentation and             HTML    101K 
                Significant Accounting Policies (Policies)                       
34: R19         (Loss) Earnings per Share of Common Stock (Tables)  HTML     50K 
35: R20         Real Estate and Intangible Assets (Tables)          HTML    126K 
36: R21         Real Estate Dispositions, Held for Sale, and        HTML     56K 
                Impairment Charges (Tables)                                      
37: R22         Mortgage Notes Payable and Credit Facility          HTML    144K 
                (Tables)                                                         
38: R23         Commitments and Contingencies (Tables)              HTML     34K 
39: R24         Equity and Mezzanine Equity (Tables)                HTML     77K 
40: R25         Subsequent Events (Tables)                          HTML     48K 
41: R26         Organization, Basis of Presentation and             HTML     96K 
                Significant Accounting Policies - Additional                     
                Information (Details)                                            
42: R27         Related-Party Transactions (Details)                HTML    109K 
43: R28         (Loss) Earnings per Share of Common Stock           HTML     65K 
                (Details)                                                        
44: R29         Real Estate and Intangible Assets - Components of   HTML     43K 
                Investments in Real Estate (Details)                             
45: R30         Real Estate and Intangible Assets - Summary of      HTML    148K 
                Properties Acquired (Details)                                    
46: R31         Real Estate and Intangible Assets - Fair Value of   HTML     52K 
                Acquired Assets and Liabilities Assumed (Details)                
47: R32         Real Estate and Intangible Assets - Future          HTML     40K 
                Operating Lease Payments from Tenants under                      
                Non-Cancelable Leases (Details)                                  
48: R33         Real Estate and Intangible Assets - Lease Revenue   HTML     33K 
                (Details)                                                        
49: R34         Real Estate and Intangible Assets - Legal           HTML     26K 
                Settlement (Details)                                             
50: R35         Real Estate and Intangible Assets - Carrying Value  HTML     51K 
                of Intangible Assets and Accumulated Amortization                
                (Details)                                                        
51: R36         Real Estate and Intangible Assets - Weighted        HTML     38K 
                Average Amortization Period for Intangible Assets                
                Acquired and Liabilities Assumed (Details)                       
52: R37         Real Estate and Intangible Assets - Estimated       HTML     40K 
                Aggregate Amortization Expense (Details)                         
53: R38         Real Estate and Intangible Assets - Summary of      HTML     46K 
                Estimated Aggregate Rental Income (Details)                      
54: R39         Real Estate Dispositions, Held for Sale, and        HTML     41K 
                Impairment Charges - Summary of Properties Sold                  
                (Details)                                                        
55: R40         Real Estate Dispositions, Held for Sale, and        HTML     46K 
                Impairment Charges - Components of Operating                     
                Income from Real Estate and Related Assets                       
                Disposed (Details)                                               
56: R41         Real Estate Dispositions, Held for Sale, and        HTML     38K 
                Impairment Charges - Additional Information                      
                (Details)                                                        
57: R42         Real Estate Dispositions, Held for Sale, and        HTML     32K 
                Impairment Charges - Components of Assets and                    
                Liabilities Held for Sale (Details)                              
58: R43         Mortgage Notes Payable and Credit Facility -        HTML    130K 
                Additional Information (Details)                                 
59: R44         Mortgage Notes Payable and Credit Facility -        HTML     94K 
                Company's Mortgage Notes Payable and Line of                     
                Credit (Details)                                                 
60: R45         Mortgage Notes Payable and Credit Facility -        HTML     96K 
                Mortgage Notes Payable (Details)                                 
61: R46         Mortgage Notes Payable and Credit Facility -        HTML     52K 
                Schedule of Principal Payments of Mortgage Notes                 
                Payable (Details)                                                
62: R47         Mortgage Notes Payable and Credit Facility -        HTML     45K 
                Interest Rate Caps and Swaps (Details)                           
63: R48         Mortgage Notes Payable and Credit Facility -        HTML     35K 
                Derivative Instruments Impact (Details)                          
64: R49         Mortgage Notes Payable and Credit Facility -        HTML     38K 
                Derivative Instruments Additional Information                    
                (Details)                                                        
65: R50         Commitments and Contingencies - Additional          HTML     40K 
                Information (Details)                                            
66: R51         Commitments and Contingencies - Future Lease        HTML     44K 
                Payments Due Under Operating Leases (Details)                    
67: R52         Equity and Mezzanine Equity - Dividends Declared    HTML     41K 
                (Details)                                                        
68: R53         Equity and Mezzanine Equity - Summary of Changes    HTML     58K 
                in Stockholders' Equity (Details)                                
69: R54         Equity and Mezzanine Equity - Additional            HTML    159K 
                Information (Details)                                            
70: R55         Subsequent Events - Monthly Distributions Declared  HTML     55K 
                by Company's Board of Directors (Details)                        
71: R56         Subsequent Events - Additional Information          HTML     37K 
                (Details)                                                        
72: R57         Schedule III - Real Estate and Accumulated          HTML   1.02M 
                Depreciation (Details)                                           
73: R58         Schedule III - Real Estate and Accumulated          HTML     37K 
                Depreciation Footnote Narrative (Details)                        
74: R59         Schedule III - Real Estate and Accumulated          HTML     39K 
                Depreciation - Change in Balance of Real Estate                  
                (Details)                                                        
75: R60         Schedule III - Real Estate and Accumulated          HTML     28K 
                Depreciation - Change in Balance of Real Estate                  
                Footnote Narrative (Details)                                     
76: R61         Schedule III - Real Estate and Accumulated          HTML     32K 
                Depreciation - Change in Balance of Accumulated                  
                Depreciation (Details)                                           
77: R62         Schedule III - Real Estate and Accumulated          HTML     28K 
                Depreciation - Change in Balance of Accumulated                  
                Depreciation Footnote Narrative (Details)                        
80: XML         IDEA XML File -- Filing Summary                      XML    146K 
78: XML         XBRL Instance -- good-20221231_htm                   XML   5.13M 
79: EXCEL       IDEA Workbook of Financial Reports                  XLSX    260K 
12: EX-101.CAL  XBRL Calculations -- good-20221231_cal               XML    245K 
13: EX-101.DEF  XBRL Definitions -- good-20221231_def                XML   1.13M 
14: EX-101.LAB  XBRL Labels -- good-20221231_lab                     XML   2.48M 
15: EX-101.PRE  XBRL Presentations -- good-20221231_pre              XML   1.45M 
11: EX-101.SCH  XBRL Schema -- good-20221231                         XSD    325K 
81: JSON        XBRL Instance as JSON Data -- MetaLinks              508±   835K 
82: ZIP         XBRL Zipped Folder -- 0001234006-23-000003-xbrl      Zip    893K

‘EX-101.LAB’ — XBRL Labels — good-20221231_lab

This Exhibit is an XBRL XML File.

<?xml version="1.0" encoding="windows-1252"?>

<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">

<link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedPeriodStartLabel" xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedPeriodStartLabel"/>

<link:roleRef roleURI="http://www.xbrl.org/2009/role/netLabel" xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/net-2009-12-16.xsd#netLabel"/>

<link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedNetLabel" xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedNetLabel"/>

<link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedTerseLabel"/>

<link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedPeriodEndLabel" xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedPeriodEndLabel"/>

<link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedLabel"/>

<link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedTotalLabel"/>

<link:labelLink xlink:role="http://www.xbrl.org/2003/role/link" xlink:type="extended">

<link:label id="lab_good_VariableRateMortgageLoansWithExtendedMaturityMember_33fc365d-009d-404a-a8d2-5d6c90ea7f57_terseLabel_en-US" xlink:label="lab_good_VariableRateMortgageLoansWithExtendedMaturityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate Mortgage Loans With Extended Maturity </link:label>

<link:label id="lab_good_VariableRateMortgageLoansWithExtendedMaturityMember_label_en-US" xlink:label="lab_good_VariableRateMortgageLoansWithExtendedMaturityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate Mortgage Loans With Extended Maturity [Member] </link:label>

<link:label id="lab_good_VariableRateMortgageLoansWithExtendedMaturityMember_documentation_en-US" xlink:label="lab_good_VariableRateMortgageLoansWithExtendedMaturityMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate Mortgage Loans With Extended Maturity </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_VariableRateMortgageLoansWithExtendedMaturityMember" xlink:href="good-20221231.xsd#good_VariableRateMortgageLoansWithExtendedMaturityMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_VariableRateMortgageLoansWithExtendedMaturityMember" xlink:to="lab_good_VariableRateMortgageLoansWithExtendedMaturityMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_RealEstateAndAccumulatedDepreciationFourthYearOfConstructionOrImprovements_1b7e94d8-8071-4cb5-a820-7bba6f299cef_terseLabel_en-US" xlink:label="lab_good_RealEstateAndAccumulatedDepreciationFourthYearOfConstructionOrImprovements" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Year construction/improvements three </link:label>

<link:label id="lab_good_RealEstateAndAccumulatedDepreciationFourthYearOfConstructionOrImprovements_label_en-US" xlink:label="lab_good_RealEstateAndAccumulatedDepreciationFourthYearOfConstructionOrImprovements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate And Accumulated Depreciation Fourth Year Of Construction Or Improvements </link:label>

<link:label id="lab_good_RealEstateAndAccumulatedDepreciationFourthYearOfConstructionOrImprovements_documentation_en-US" xlink:label="lab_good_RealEstateAndAccumulatedDepreciationFourthYearOfConstructionOrImprovements" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate And Accumulated Depreciation Fourth Year Of Construction Or Improvements </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_RealEstateAndAccumulatedDepreciationFourthYearOfConstructionOrImprovements" xlink:href="good-20221231.xsd#good_RealEstateAndAccumulatedDepreciationFourthYearOfConstructionOrImprovements"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_RealEstateAndAccumulatedDepreciationFourthYearOfConstructionOrImprovements" xlink:to="lab_good_RealEstateAndAccumulatedDepreciationFourthYearOfConstructionOrImprovements" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RelatedPartyTransactionsAbstract_a1513bc3-bbbe-43cf-8459-1aad34ad98f3_terseLabel_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Related Party Transactions [Abstract] </link:label>

<link:label id="lab_us-gaap_RelatedPartyTransactionsAbstract_label_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Related Party Transactions [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RelatedPartyTransactionsAbstract" xlink:to="lab_us-gaap_RelatedPartyTransactionsAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ProvisionForDoubtfulAccounts_0241cfd5-8bdc-42a2-baf1-83eb28476649_terseLabel_en-US" xlink:label="lab_us-gaap_ProvisionForDoubtfulAccounts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Bad debt expense </link:label>

<link:label id="lab_us-gaap_ProvisionForDoubtfulAccounts_label_en-US" xlink:label="lab_us-gaap_ProvisionForDoubtfulAccounts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts Receivable, Credit Loss Expense (Reversal) </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProvisionForDoubtfulAccounts"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProvisionForDoubtfulAccounts" xlink:to="lab_us-gaap_ProvisionForDoubtfulAccounts" xlink:type="arc" order="1"/>

<link:label id="lab_good_CantonNorthCarolinaCommercialAndManufacturingBuildingMember_7f573f1d-2f97-4797-928a-4b9c5a13b7ad_terseLabel_en-US" xlink:label="lab_good_CantonNorthCarolinaCommercialAndManufacturingBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Canton, North Carolina Industrial Building </link:label>

<link:label id="lab_good_CantonNorthCarolinaCommercialAndManufacturingBuildingMember_label_en-US" xlink:label="lab_good_CantonNorthCarolinaCommercialAndManufacturingBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Canton North Carolina Commercial And Manufacturing Building [Member] </link:label>

<link:label id="lab_good_CantonNorthCarolinaCommercialAndManufacturingBuildingMember_documentation_en-US" xlink:label="lab_good_CantonNorthCarolinaCommercialAndManufacturingBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Canton North Carolina commercial and manufacturing building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CantonNorthCarolinaCommercialAndManufacturingBuildingMember" xlink:href="good-20221231.xsd#good_CantonNorthCarolinaCommercialAndManufacturingBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CantonNorthCarolinaCommercialAndManufacturingBuildingMember" xlink:to="lab_good_CantonNorthCarolinaCommercialAndManufacturingBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_AlbuquerqueNewMexicoIndustrialBuildingTwoMember_345e5f87-2458-462e-80de-8f51de4d8e46_terseLabel_en-US" xlink:label="lab_good_AlbuquerqueNewMexicoIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Albuquerque, New Mexico Industrial Building Two </link:label>

<link:label id="lab_good_AlbuquerqueNewMexicoIndustrialBuildingTwoMember_label_en-US" xlink:label="lab_good_AlbuquerqueNewMexicoIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Albuquerque, New Mexico Industrial Building Two [Member] </link:label>

<link:label id="lab_good_AlbuquerqueNewMexicoIndustrialBuildingTwoMember_documentation_en-US" xlink:label="lab_good_AlbuquerqueNewMexicoIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Albuquerque, New Mexico Industrial Building Two [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AlbuquerqueNewMexicoIndustrialBuildingTwoMember" xlink:href="good-20221231.xsd#good_AlbuquerqueNewMexicoIndustrialBuildingTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AlbuquerqueNewMexicoIndustrialBuildingTwoMember" xlink:to="lab_good_AlbuquerqueNewMexicoIndustrialBuildingTwoMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DebtInstrumentCarryingAmount_54868c00-cfa3-4a7a-a73f-713f15e1e694_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentCarryingAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Carrying value </link:label>

<link:label id="lab_us-gaap_DebtInstrumentCarryingAmount_e7a09ca6-d6f3-4799-9fb1-4a145fe10fa6_totalLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentCarryingAmount" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Carrying value </link:label>

<link:label id="lab_us-gaap_DebtInstrumentCarryingAmount_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentCarryingAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Gross </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentCarryingAmount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentCarryingAmount" xlink:to="lab_us-gaap_DebtInstrumentCarryingAmount" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract_cbaf8fea-5c56-4c9f-a50b-f5801b654918_terseLabel_en-US" xlink:label="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Assets Held for Sale </link:label>

<link:label id="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract_label_en-US" xlink:label="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Group, Including Discontinued Operation, Assets [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:to="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_LessorOperatingLeaseGroundLeaseAmortization_73d47b6c-eafa-4d68-a889-6b037bcd46ee_terseLabel_en-US" xlink:label="lab_good_LessorOperatingLeaseGroundLeaseAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ground lease amortization </link:label>

<link:label id="lab_good_LessorOperatingLeaseGroundLeaseAmortization_label_en-US" xlink:label="lab_good_LessorOperatingLeaseGroundLeaseAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessor, Operating Lease, Ground Lease Amortization </link:label>

<link:label id="lab_good_LessorOperatingLeaseGroundLeaseAmortization_documentation_en-US" xlink:label="lab_good_LessorOperatingLeaseGroundLeaseAmortization" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessor, Operating Lease, Ground Lease Amortization </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_LessorOperatingLeaseGroundLeaseAmortization" xlink:href="good-20221231.xsd#good_LessorOperatingLeaseGroundLeaseAmortization"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_LessorOperatingLeaseGroundLeaseAmortization" xlink:to="lab_good_LessorOperatingLeaseGroundLeaseAmortization" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfStockholdersEquityTableTextBlock_cd40efe7-4e8f-4be4-a88c-84105e626d07_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfStockholdersEquityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Summary of Changes in Stockholders' Equity </link:label>

<link:label id="lab_us-gaap_ScheduleOfStockholdersEquityTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfStockholdersEquityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Stockholders Equity [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockholdersEquityTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfStockholdersEquityTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfStockholdersEquityTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfStockholdersEquityTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_SeriesFCumulativeRedeemablePreferredStockMember_65e78ccc-d29b-4ae6-87a4-6ea3d6430d31_terseLabel_en-US" xlink:label="lab_good_SeriesFCumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series F Cumulative Redeemable Preferred Stock </link:label>

<link:label id="lab_good_SeriesFCumulativeRedeemablePreferredStockMember_label_en-US" xlink:label="lab_good_SeriesFCumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series F Cumulative Redeemable Preferred Stock [Member] </link:label>

<link:label id="lab_good_SeriesFCumulativeRedeemablePreferredStockMember_documentation_en-US" xlink:label="lab_good_SeriesFCumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series F Cumulative Redeemable Preferred Stock [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SeriesFCumulativeRedeemablePreferredStockMember" xlink:href="good-20221231.xsd#good_SeriesFCumulativeRedeemablePreferredStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SeriesFCumulativeRedeemablePreferredStockMember" xlink:to="lab_good_SeriesFCumulativeRedeemablePreferredStockMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PreferredStockSharesOutstanding_b423d1bd-4422-4b5c-a8de-426768a70f98_periodStartLabel_en-US" xlink:label="lab_us-gaap_PreferredStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred stock, beginning balance (in shares) </link:label>

<link:label id="lab_us-gaap_PreferredStockSharesOutstanding_40244bdc-45c5-4a0b-989b-1f034e6517b6_periodEndLabel_en-US" xlink:label="lab_us-gaap_PreferredStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred stock, ending balance (in shares) </link:label>

<link:label id="lab_us-gaap_PreferredStockSharesOutstanding_label_en-US" xlink:label="lab_us-gaap_PreferredStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred Stock, Shares Outstanding </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockSharesOutstanding"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockSharesOutstanding" xlink:to="lab_us-gaap_PreferredStockSharesOutstanding" xlink:type="arc" order="1"/>

<link:label id="lab_good_IncentiveFee_fe9e3a24-1320-49a8-9292-fea34f47bbff_verboseLabel_en-US" xlink:label="lab_good_IncentiveFee" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Incentive fee </link:label>

<link:label id="lab_good_IncentiveFee_label_en-US" xlink:label="lab_good_IncentiveFee" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Incentive Fee </link:label>

<link:label id="lab_good_IncentiveFee_documentation_en-US" xlink:label="lab_good_IncentiveFee" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Incentive fee. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_IncentiveFee" xlink:href="good-20221231.xsd#good_IncentiveFee"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_IncentiveFee" xlink:to="lab_good_IncentiveFee" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DebtInstrumentAxis_19ac8562-293e-403f-aba5-38c4a897fcc7_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument [Axis] </link:label>

<link:label id="lab_us-gaap_DebtInstrumentAxis_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentAxis" xlink:to="lab_us-gaap_DebtInstrumentAxis" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateHeldForDevelopmentAndSalePolicy_e9f8b901-442a-4234-a2e3-0646ae9dfe54_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstateHeldForDevelopmentAndSalePolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Held for Sale Property </link:label>

<link:label id="lab_us-gaap_RealEstateHeldForDevelopmentAndSalePolicy_label_en-US" xlink:label="lab_us-gaap_RealEstateHeldForDevelopmentAndSalePolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Held for Development and Sale, Policy [Policy Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateHeldForDevelopmentAndSalePolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateHeldForDevelopmentAndSalePolicy"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateHeldForDevelopmentAndSalePolicy" xlink:to="lab_us-gaap_RealEstateHeldForDevelopmentAndSalePolicy" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateInvestmentPropertyAtCost_88a5f4ac-726d-4a3f-9814-c4191dc8b23c_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstateInvestmentPropertyAtCost" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real estate, at cost </link:label>

<link:label id="lab_us-gaap_RealEstateInvestmentPropertyAtCost_label_en-US" xlink:label="lab_us-gaap_RealEstateInvestmentPropertyAtCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Investment Property, at Cost </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateInvestmentPropertyAtCost" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateInvestmentPropertyAtCost"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateInvestmentPropertyAtCost" xlink:to="lab_us-gaap_RealEstateInvestmentPropertyAtCost" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AmortizationOfBelowMarketLease_750d8286-69cc-4c7b-9cb1-a320af8ed1fa_terseLabel_en-US" xlink:label="lab_us-gaap_AmortizationOfBelowMarketLease" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization related to below-market lease </link:label>

<link:label id="lab_us-gaap_AmortizationOfBelowMarketLease_label_en-US" xlink:label="lab_us-gaap_AmortizationOfBelowMarketLease" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of Below Market Lease </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfBelowMarketLease" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AmortizationOfBelowMarketLease"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AmortizationOfBelowMarketLease" xlink:to="lab_us-gaap_AmortizationOfBelowMarketLease" xlink:type="arc" order="1"/>

<link:label id="lab_good_PercentageOfAnnualRealEstateInvestmentTrustTaxableIncomeDistributeToStockholders_d8c8ada4-e11d-42fb-a963-d1b354a1b7d4_terseLabel_en-US" xlink:label="lab_good_PercentageOfAnnualRealEstateInvestmentTrustTaxableIncomeDistributeToStockholders" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> REIT taxable income to its stockholders (as percent) </link:label>

<link:label id="lab_good_PercentageOfAnnualRealEstateInvestmentTrustTaxableIncomeDistributeToStockholders_label_en-US" xlink:label="lab_good_PercentageOfAnnualRealEstateInvestmentTrustTaxableIncomeDistributeToStockholders" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage Of Annual Real Estate Investment Trust Taxable Income Distribute To Stockholders </link:label>

<link:label id="lab_good_PercentageOfAnnualRealEstateInvestmentTrustTaxableIncomeDistributeToStockholders_documentation_en-US" xlink:label="lab_good_PercentageOfAnnualRealEstateInvestmentTrustTaxableIncomeDistributeToStockholders" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of annual real estate investment trust taxable income distribute to stockholders. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PercentageOfAnnualRealEstateInvestmentTrustTaxableIncomeDistributeToStockholders" xlink:href="good-20221231.xsd#good_PercentageOfAnnualRealEstateInvestmentTrustTaxableIncomeDistributeToStockholders"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PercentageOfAnnualRealEstateInvestmentTrustTaxableIncomeDistributeToStockholders" xlink:to="lab_good_PercentageOfAnnualRealEstateInvestmentTrustTaxableIncomeDistributeToStockholders" xlink:type="arc" order="1"/>

<link:label id="lab_good_VariableRateMortgagesMember_8c6f9443-fa95-49c1-9131-d13183a982ec_terseLabel_en-US" xlink:label="lab_good_VariableRateMortgagesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable rate mortgage loans </link:label>

<link:label id="lab_good_VariableRateMortgagesMember_label_en-US" xlink:label="lab_good_VariableRateMortgagesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate Mortgages [Member] </link:label>

<link:label id="lab_good_VariableRateMortgagesMember_documentation_en-US" xlink:label="lab_good_VariableRateMortgagesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable rate mortgages. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_VariableRateMortgagesMember" xlink:href="good-20221231.xsd#good_VariableRateMortgagesMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_VariableRateMortgagesMember" xlink:to="lab_good_VariableRateMortgagesMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateDisclosureTextBlock_33476913-39ee-4216-bb29-8151d083be81_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstateDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Dispositions, Held for Sale, and Impairment Charges </link:label>

<link:label id="lab_us-gaap_RealEstateDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_RealEstateDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Disclosure [Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateDisclosureTextBlock" xlink:to="lab_us-gaap_RealEstateDisclosureTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LeaseIncome_2dc0f379-8f31-4de5-b907-e760255ae78e_terseLabel_en-US" xlink:label="lab_us-gaap_LeaseIncome" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease revenue </link:label>

<link:label id="lab_us-gaap_LeaseIncome_label_en-US" xlink:label="lab_us-gaap_LeaseIncome" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease Income </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseIncome" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LeaseIncome"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LeaseIncome" xlink:to="lab_us-gaap_LeaseIncome" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AdditionalPaidInCapital_179eb322-3816-4c06-b92b-0728d113ef4c_terseLabel_en-US" xlink:label="lab_us-gaap_AdditionalPaidInCapital" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Additional paid in capital </link:label>

<link:label id="lab_us-gaap_AdditionalPaidInCapital_label_en-US" xlink:label="lab_us-gaap_AdditionalPaidInCapital" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Additional Paid in Capital </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdditionalPaidInCapital"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AdditionalPaidInCapital" xlink:to="lab_us-gaap_AdditionalPaidInCapital" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue_af03fa29-fa6c-4463-98cf-516d6ddbde2c_terseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating revenue </link:label>

<link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue_label_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Group, Including Discontinued Operation, Revenue </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue" xlink:to="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfDividendsPayableTextBlock_23fae798-570b-47a5-b40d-311c6ce19937_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfDividendsPayableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividends Declared </link:label>

<link:label id="lab_us-gaap_ScheduleOfDividendsPayableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfDividendsPayableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Dividends Payable [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDividendsPayableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfDividendsPayableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfDividendsPayableTextBlock" xlink:to="lab_us-gaap_ScheduleOfDividendsPayableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_RealEstateAndIntangibleAssetsDisclosureTextBlock_ef405b8f-711d-482b-aa4d-4bce13813be8_terseLabel_en-US" xlink:label="lab_good_RealEstateAndIntangibleAssetsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate and Intangible Assets </link:label>

<link:label id="lab_good_RealEstateAndIntangibleAssetsDisclosureTextBlock_label_en-US" xlink:label="lab_good_RealEstateAndIntangibleAssetsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate and Intangible Assets Disclosure [Text Block] </link:label>

<link:label id="lab_good_RealEstateAndIntangibleAssetsDisclosureTextBlock_documentation_en-US" xlink:label="lab_good_RealEstateAndIntangibleAssetsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate and Intangible Assets Disclosure [Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_RealEstateAndIntangibleAssetsDisclosureTextBlock" xlink:href="good-20221231.xsd#good_RealEstateAndIntangibleAssetsDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_RealEstateAndIntangibleAssetsDisclosureTextBlock" xlink:to="lab_good_RealEstateAndIntangibleAssetsDisclosureTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_cd6348ff-c7a0-4f45-af6d-c768da45dc40_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Spread on LIBOR </link:label>

<link:label id="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_00896ff0-e0f1-415b-9f6c-20c04c6fadd1_verboseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Interest Rate on Variable Rate Debt Repaid </link:label>

<link:label id="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Basis Spread on Variable Rate </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:to="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SeriesDPreferredStockMember_b591cff4-31db-4378-9361-2c77a5dea642_verboseLabel_en-US" xlink:label="lab_us-gaap_SeriesDPreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series D Preferred Stock </link:label>

<link:label id="lab_us-gaap_SeriesDPreferredStockMember_label_en-US" xlink:label="lab_us-gaap_SeriesDPreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series D Preferred Stock [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesDPreferredStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeriesDPreferredStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SeriesDPreferredStockMember" xlink:to="lab_us-gaap_SeriesDPreferredStockMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_Depreciation_83249355-c662-4511-b185-4f18ee512625_verboseLabel_en-US" xlink:label="lab_us-gaap_Depreciation" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Depreciation </link:label>

<link:label id="lab_us-gaap_Depreciation_label_en-US" xlink:label="lab_us-gaap_Depreciation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Depreciation </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Depreciation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Depreciation" xlink:to="lab_us-gaap_Depreciation" xlink:type="arc" order="1"/>

<link:label id="lab_good_ColumbusOhioIndustrialBuildingMember_d584c79b-e355-4c6b-96df-925b158e1307_terseLabel_en-US" xlink:label="lab_good_ColumbusOhioIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbus, Ohio Industrial Building </link:label>

<link:label id="lab_good_ColumbusOhioIndustrialBuildingMember_label_en-US" xlink:label="lab_good_ColumbusOhioIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbus, Ohio Industrial Building [Member] </link:label>

<link:label id="lab_good_ColumbusOhioIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_ColumbusOhioIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbus, Ohio Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ColumbusOhioIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_ColumbusOhioIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ColumbusOhioIndustrialBuildingMember" xlink:to="lab_good_ColumbusOhioIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_bd7c6167-f4aa-44ea-8577-e23707b90af2_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted average discount rate </link:label>

<link:label id="lab_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Lease, Weighted Average Discount Rate, Percent </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:to="lab_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage_7bdb12ff-208f-4bf9-8ba6-911cff8f20c2_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stated interest rate </link:label>

<link:label id="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Interest Rate, Stated Percentage </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:to="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstatePropertiesDomain_85290f2d-6654-4b9d-9828-447c1cc85195_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstatePropertiesDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Properties [Domain] </link:label>

<link:label id="lab_us-gaap_RealEstatePropertiesDomain_label_en-US" xlink:label="lab_us-gaap_RealEstatePropertiesDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Properties [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstatePropertiesDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstatePropertiesDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstatePropertiesDomain" xlink:to="lab_us-gaap_RealEstatePropertiesDomain" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_TemporaryEquitySharesOutstanding_b731404b-3976-4571-9ac4-e714804a6fcd_terseLabel_en-US" xlink:label="lab_us-gaap_TemporaryEquitySharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Redeemable preferred stock, shares outstanding (in shares) </link:label>

<link:label id="lab_us-gaap_TemporaryEquitySharesOutstanding_label_en-US" xlink:label="lab_us-gaap_TemporaryEquitySharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Temporary Equity, Shares Outstanding </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TemporaryEquitySharesOutstanding"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TemporaryEquitySharesOutstanding" xlink:to="lab_us-gaap_TemporaryEquitySharesOutstanding" xlink:type="arc" order="1"/>

<link:label id="lab_good_RemainingTermOfInPlaceLeasesAndUnamortizedLease_5c2e20ce-3f7b-4658-9df6-056eb1ab3316_terseLabel_en-US" xlink:label="lab_good_RemainingTermOfInPlaceLeasesAndUnamortizedLease" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Remaining term of in-place leases and unamortized lease </link:label>

<link:label id="lab_good_RemainingTermOfInPlaceLeasesAndUnamortizedLease_label_en-US" xlink:label="lab_good_RemainingTermOfInPlaceLeasesAndUnamortizedLease" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Remaining Term Of In Place Leases And Unamortized Lease </link:label>

<link:label id="lab_good_RemainingTermOfInPlaceLeasesAndUnamortizedLease_documentation_en-US" xlink:label="lab_good_RemainingTermOfInPlaceLeasesAndUnamortizedLease" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Remaining term of in place leases and unamortized lease. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_RemainingTermOfInPlaceLeasesAndUnamortizedLease" xlink:href="good-20221231.xsd#good_RemainingTermOfInPlaceLeasesAndUnamortizedLease"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_RemainingTermOfInPlaceLeasesAndUnamortizedLease" xlink:to="lab_good_RemainingTermOfInPlaceLeasesAndUnamortizedLease" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination_8b2a8f14-c6a3-4b0e-ab69-faee8e8e31c9_terseLabel_en-US" xlink:label="lab_us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Issuance of Non-controlling OP Units as consideration in real estate acquisitions, net </link:label>

<link:label id="lab_us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination_label_en-US" xlink:label="lab_us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncontrolling Interest, Increase from Business Combination </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination" xlink:to="lab_us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination" xlink:type="arc" order="1"/>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances_a28f4890-4985-466e-a554-9cf0f1d4e137_terseLabel_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Encumbrances, initial cost </link:label>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances_label_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances" xlink:to="lab_srt_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_93dbceba-9392-416f-b737-f4dde3fbb8f1_terseLabel_en-US" xlink:label="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] </link:label>

<link:label id="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_label_en-US" xlink:label="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:to="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_10fddec8-203d-43fe-bfb6-800dfb650e19_terseLabel_en-US" xlink:label="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Anti-dilutive convertible shares of senior common stock excluded from calculation of diluted earnings per share (in shares) </link:label>

<link:label id="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_label_en-US" xlink:label="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:to="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:type="arc" order="1"/>

<link:label id="lab_good_ColumbiaSouthCarolinaOfficeMember_82a4c684-0087-4089-908a-2249b125ec9b_terseLabel_en-US" xlink:label="lab_good_ColumbiaSouthCarolinaOfficeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbia, South Carolina Office Building </link:label>

<link:label id="lab_good_ColumbiaSouthCarolinaOfficeMember_label_en-US" xlink:label="lab_good_ColumbiaSouthCarolinaOfficeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbia South Carolina Office [Member] </link:label>

<link:label id="lab_good_ColumbiaSouthCarolinaOfficeMember_documentation_en-US" xlink:label="lab_good_ColumbiaSouthCarolinaOfficeMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbia South Carolina office. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ColumbiaSouthCarolinaOfficeMember" xlink:href="good-20221231.xsd#good_ColumbiaSouthCarolinaOfficeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ColumbiaSouthCarolinaOfficeMember" xlink:to="lab_good_ColumbiaSouthCarolinaOfficeMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_BelowMarketLeaseGross_151beca8-a660-47ab-ac52-143a1aad41ae_negatedLabel_en-US" xlink:label="lab_us-gaap_BelowMarketLeaseGross" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Below market leases, gross </link:label>

<link:label id="lab_us-gaap_BelowMarketLeaseGross_label_en-US" xlink:label="lab_us-gaap_BelowMarketLeaseGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Below Market Lease, Gross </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BelowMarketLeaseGross" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BelowMarketLeaseGross"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BelowMarketLeaseGross" xlink:to="lab_us-gaap_BelowMarketLeaseGross" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_901ab503-ec9e-45cc-9c66-94d44734ee9a_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Future Lease Payments Due Under Operating Leases </link:label>

<link:label id="lab_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, to be Paid [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:to="lab_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateAccumulatedDepreciationOtherDeductions_0a2dae72-6012-457d-abd2-d7dd327baf2d_negatedLabel_en-US" xlink:label="lab_us-gaap_RealEstateAccumulatedDepreciationOtherDeductions" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dispositions during period </link:label>

<link:label id="lab_us-gaap_RealEstateAccumulatedDepreciationOtherDeductions_label_en-US" xlink:label="lab_us-gaap_RealEstateAccumulatedDepreciationOtherDeductions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation, Other Deduction </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateAccumulatedDepreciationOtherDeductions" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateAccumulatedDepreciationOtherDeductions"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateAccumulatedDepreciationOtherDeductions" xlink:to="lab_us-gaap_RealEstateAccumulatedDepreciationOtherDeductions" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_e9df1111-c957-4cce-bfc2-17cb1e3b9699_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Thereafter </link:label>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, to be Paid, after Year Five </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LegalEntityTypeOfCounterpartyDomain_67b17862-0bb4-4a80-83e2-7971ce6edc54_terseLabel_en-US" xlink:label="lab_us-gaap_LegalEntityTypeOfCounterpartyDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Legal Entity Type of Counterparty [Domain] </link:label>

<link:label id="lab_us-gaap_LegalEntityTypeOfCounterpartyDomain_label_en-US" xlink:label="lab_us-gaap_LegalEntityTypeOfCounterpartyDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Legal Entity Type of Counterparty [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LegalEntityTypeOfCounterpartyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LegalEntityTypeOfCounterpartyDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LegalEntityTypeOfCounterpartyDomain" xlink:to="lab_us-gaap_LegalEntityTypeOfCounterpartyDomain" xlink:type="arc" order="1"/>

<link:label id="lab_good_BusinessAcquisitionExpenses_cc68e965-c9b2-461e-8da4-bd5009f82d04_terseLabel_en-US" xlink:label="lab_good_BusinessAcquisitionExpenses" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate Capitalized Acquisition Costs </link:label>

<link:label id="lab_good_BusinessAcquisitionExpenses_label_en-US" xlink:label="lab_good_BusinessAcquisitionExpenses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Acquisition Expenses </link:label>

<link:label id="lab_good_BusinessAcquisitionExpenses_documentation_en-US" xlink:label="lab_good_BusinessAcquisitionExpenses" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business acquisition expenses. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BusinessAcquisitionExpenses" xlink:href="good-20221231.xsd#good_BusinessAcquisitionExpenses"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BusinessAcquisitionExpenses" xlink:to="lab_good_BusinessAcquisitionExpenses" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_EquityComponentDomain_2dee041c-7a25-4448-aef0-3d2b117feafa_terseLabel_en-US" xlink:label="lab_us-gaap_EquityComponentDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equity Component [Domain] </link:label>

<link:label id="lab_us-gaap_EquityComponentDomain_label_en-US" xlink:label="lab_us-gaap_EquityComponentDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equity Component [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EquityComponentDomain" xlink:to="lab_us-gaap_EquityComponentDomain" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SubsequentEventTypeDomain_09bd8b33-1046-48bf-befe-b99e56f53f30_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsequent Event Type [Domain] </link:label>

<link:label id="lab_us-gaap_SubsequentEventTypeDomain_label_en-US" xlink:label="lab_us-gaap_SubsequentEventTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsequent Event Type [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventTypeDomain" xlink:to="lab_us-gaap_SubsequentEventTypeDomain" xlink:type="arc" order="1"/>

<link:label id="lab_srt_OwnershipAxis_132a4ef9-fbc6-466f-8458-a7cd427e8cc4_terseLabel_en-US" xlink:label="lab_srt_OwnershipAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ownership [Axis] </link:label>

<link:label id="lab_srt_OwnershipAxis_label_en-US" xlink:label="lab_srt_OwnershipAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ownership [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_OwnershipAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_OwnershipAxis" xlink:to="lab_srt_OwnershipAxis" xlink:type="arc" order="1"/>

<link:label id="lab_good_BlaineMinnesotaOfficeBuildingMember_f9947dac-4281-4ee1-b496-2380a57e9873_terseLabel_en-US" xlink:label="lab_good_BlaineMinnesotaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Blaine, Minnesota Office Building </link:label>

<link:label id="lab_good_BlaineMinnesotaOfficeBuildingMember_label_en-US" xlink:label="lab_good_BlaineMinnesotaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Blaine Minnesota Office Building [Member] </link:label>

<link:label id="lab_good_BlaineMinnesotaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_BlaineMinnesotaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Blaine Minnesota Office Building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BlaineMinnesotaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_BlaineMinnesotaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BlaineMinnesotaOfficeBuildingMember" xlink:to="lab_good_BlaineMinnesotaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PaymentsOfFinancingCosts_f0e1c886-76f9-4671-ba4d-2a230080fb1a_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsOfFinancingCosts" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments for deferred financing costs </link:label>

<link:label id="lab_us-gaap_PaymentsOfFinancingCosts_2d35b2fd-4c64-45ed-b071-bbaeeef7d7e7_terseLabel_en-US" xlink:label="lab_us-gaap_PaymentsOfFinancingCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments of deferred financing costs </link:label>

<link:label id="lab_us-gaap_PaymentsOfFinancingCosts_label_en-US" xlink:label="lab_us-gaap_PaymentsOfFinancingCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments of Financing Costs </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfFinancingCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsOfFinancingCosts"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsOfFinancingCosts" xlink:to="lab_us-gaap_PaymentsOfFinancingCosts" xlink:type="arc" order="1"/>

<link:label id="lab_good_DetroitMichiganIndustrialBuildingTwoMember_b2d9a60a-3af2-417b-b1a3-06f1bdc592bb_terseLabel_en-US" xlink:label="lab_good_DetroitMichiganIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Detroit, Michigan Industrial Building Two </link:label>

<link:label id="lab_good_DetroitMichiganIndustrialBuildingTwoMember_label_en-US" xlink:label="lab_good_DetroitMichiganIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Detroit, Michigan Industrial Building Two [Member] </link:label>

<link:label id="lab_good_DetroitMichiganIndustrialBuildingTwoMember_documentation_en-US" xlink:label="lab_good_DetroitMichiganIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Detroit, Michigan Industrial Building Two [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DetroitMichiganIndustrialBuildingTwoMember" xlink:href="good-20221231.xsd#good_DetroitMichiganIndustrialBuildingTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DetroitMichiganIndustrialBuildingTwoMember" xlink:to="lab_good_DetroitMichiganIndustrialBuildingTwoMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_FairValueMeasurementPolicyPolicyTextBlock_e3a03b6a-9b93-45a1-b59e-aba1d3b01142_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair Value Measurements and Disclosures </link:label>

<link:label id="lab_us-gaap_FairValueMeasurementPolicyPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair Value Measurement, Policy [Policy Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementPolicyPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:to="lab_us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_IndianapolisIndianaIndustrialBuildingMember_42a20de5-99c9-4961-8ea0-731c7bea75c8_terseLabel_en-US" xlink:label="lab_good_IndianapolisIndianaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indianapolis, Indiana Industrial Building </link:label>

<link:label id="lab_good_IndianapolisIndianaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_IndianapolisIndianaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indianapolis, Indiana Industrial Building [Member] </link:label>

<link:label id="lab_good_IndianapolisIndianaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_IndianapolisIndianaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indianapolis, Indiana Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_IndianapolisIndianaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_IndianapolisIndianaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_IndianapolisIndianaIndustrialBuildingMember" xlink:to="lab_good_IndianapolisIndianaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_ImprovementsOfExistingRealEstate_1fba52a7-a2f7-4802-b3d7-6976a51fb015_negatedLabel_en-US" xlink:label="lab_good_ImprovementsOfExistingRealEstate" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Improvements of existing real estate </link:label>

<link:label id="lab_good_ImprovementsOfExistingRealEstate_label_en-US" xlink:label="lab_good_ImprovementsOfExistingRealEstate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Improvements Of Existing Real Estate </link:label>

<link:label id="lab_good_ImprovementsOfExistingRealEstate_documentation_en-US" xlink:label="lab_good_ImprovementsOfExistingRealEstate" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Improvements of existing real estate. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ImprovementsOfExistingRealEstate" xlink:href="good-20221231.xsd#good_ImprovementsOfExistingRealEstate"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ImprovementsOfExistingRealEstate" xlink:to="lab_good_ImprovementsOfExistingRealEstate" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_HedgingDesignationDomain_c25b8781-bc8e-4b27-a583-736f1c557fb9_terseLabel_en-US" xlink:label="lab_us-gaap_HedgingDesignationDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hedging Designation [Domain] </link:label>

<link:label id="lab_us-gaap_HedgingDesignationDomain_label_en-US" xlink:label="lab_us-gaap_HedgingDesignationDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hedging Designation [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_HedgingDesignationDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_HedgingDesignationDomain" xlink:to="lab_us-gaap_HedgingDesignationDomain" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateAccumulatedDepreciationOtherAdditions_72824f40-0208-456e-8557-c28dd63d5b07_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstateAccumulatedDepreciationOtherAdditions" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Additions during period </link:label>

<link:label id="lab_us-gaap_RealEstateAccumulatedDepreciationOtherAdditions_label_en-US" xlink:label="lab_us-gaap_RealEstateAccumulatedDepreciationOtherAdditions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation, Other Addition </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateAccumulatedDepreciationOtherAdditions" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateAccumulatedDepreciationOtherAdditions"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateAccumulatedDepreciationOtherAdditions" xlink:to="lab_us-gaap_RealEstateAccumulatedDepreciationOtherAdditions" xlink:type="arc" order="1"/>

<link:label id="lab_good_PaymentsToLendersForReservesHeldInEscrow_5e680d8c-8b56-48ae-80fd-96d4500359dd_negatedLabel_en-US" xlink:label="lab_good_PaymentsToLendersForReservesHeldInEscrow" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments to lenders for funds held in escrow </link:label>

<link:label id="lab_good_PaymentsToLendersForReservesHeldInEscrow_label_en-US" xlink:label="lab_good_PaymentsToLendersForReservesHeldInEscrow" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments To Lenders For Reserves Held In Escrow </link:label>

<link:label id="lab_good_PaymentsToLendersForReservesHeldInEscrow_documentation_en-US" xlink:label="lab_good_PaymentsToLendersForReservesHeldInEscrow" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments to lenders for reserves held in escrow. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PaymentsToLendersForReservesHeldInEscrow" xlink:href="good-20221231.xsd#good_PaymentsToLendersForReservesHeldInEscrow"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PaymentsToLendersForReservesHeldInEscrow" xlink:to="lab_good_PaymentsToLendersForReservesHeldInEscrow" xlink:type="arc" order="1"/>

<link:label id="lab_good_FixedRateMortgageLoansWithExtendedMaturityMember_4b818ccf-93bc-40a6-8b1a-1a70dc277d2a_terseLabel_en-US" xlink:label="lab_good_FixedRateMortgageLoansWithExtendedMaturityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fixed Rate Mortgage Loans With Extended Maturity </link:label>

<link:label id="lab_good_FixedRateMortgageLoansWithExtendedMaturityMember_label_en-US" xlink:label="lab_good_FixedRateMortgageLoansWithExtendedMaturityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fixed Rate Mortgage Loans With Extended Maturity [Member] </link:label>

<link:label id="lab_good_FixedRateMortgageLoansWithExtendedMaturityMember_documentation_en-US" xlink:label="lab_good_FixedRateMortgageLoansWithExtendedMaturityMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fixed Rate Mortgage Loans With Extended Maturity </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_FixedRateMortgageLoansWithExtendedMaturityMember" xlink:href="good-20221231.xsd#good_FixedRateMortgageLoansWithExtendedMaturityMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_FixedRateMortgageLoansWithExtendedMaturityMember" xlink:to="lab_good_FixedRateMortgageLoansWithExtendedMaturityMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_OklahomaCityOklahomaIndustrialBuildingMember_01ba387d-1032-4e38-aa78-ea520c57b41a_terseLabel_en-US" xlink:label="lab_good_OklahomaCityOklahomaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Oklahoma City, Oklahoma Industrial Building </link:label>

<link:label id="lab_good_OklahomaCityOklahomaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_OklahomaCityOklahomaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Oklahoma City, Oklahoma Industrial Building [Member] </link:label>

<link:label id="lab_good_OklahomaCityOklahomaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_OklahomaCityOklahomaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Oklahoma City, Oklahoma Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_OklahomaCityOklahomaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_OklahomaCityOklahomaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_OklahomaCityOklahomaIndustrialBuildingMember" xlink:to="lab_good_OklahomaCityOklahomaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableLineItems_86ea0153-6496-4d1c-a4a8-3195dd722cdb_terseLabel_en-US" xlink:label="lab_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Operating Leases Future Minimum Payments Receivable [Line Items] </link:label>

<link:label id="lab_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableLineItems_label_en-US" xlink:label="lab_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Operating Leases Future Minimum Payments Receivable [Line Items] </link:label>

<link:label id="lab_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableLineItems_documentation_en-US" xlink:label="lab_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableLineItems" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Operating Leases Future Minimum Payments Receivable [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableLineItems" xlink:href="good-20221231.xsd#good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableLineItems" xlink:to="lab_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LineOfCredit_0ede8f72-49fa-41f7-a211-8ab0889e2ae4_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCredit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Borrowings under Revolver </link:label>

<link:label id="lab_us-gaap_LineOfCredit_2c2227b7-249e-4990-a6dc-374af76c464a_verboseLabel_en-US" xlink:label="lab_us-gaap_LineOfCredit" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Borrowings under revolving credit facility, net </link:label>

<link:label id="lab_us-gaap_LineOfCredit_label_en-US" xlink:label="lab_us-gaap_LineOfCredit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Line of Credit </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCredit"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCredit" xlink:to="lab_us-gaap_LineOfCredit" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityAddressStateOrProvince_b0cd8ba8-c537-4e9e-b8b8-71ef5bd9e5e6_terseLabel_en-US" xlink:label="lab_dei_EntityAddressStateOrProvince" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, State or Province </link:label>

<link:label id="lab_dei_EntityAddressStateOrProvince_label_en-US" xlink:label="lab_dei_EntityAddressStateOrProvince" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, State or Province </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressStateOrProvince"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityAddressStateOrProvince" xlink:to="lab_dei_EntityAddressStateOrProvince" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_14c4ade0-ccc4-4f9f-97da-43fcb200e6a8_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Comprehensive income </link:label>

<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive Income (Loss), Net of Tax [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:to="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_RichardsonTexasOfficeBuildingMember_f2ccfa94-0f71-4481-8b69-3bbb8ae68b2a_terseLabel_en-US" xlink:label="lab_good_RichardsonTexasOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Richardson, Texas Office Building </link:label>

<link:label id="lab_good_RichardsonTexasOfficeBuildingMember_label_en-US" xlink:label="lab_good_RichardsonTexasOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Richardson Texas Office Building [Member] </link:label>

<link:label id="lab_good_RichardsonTexasOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_RichardsonTexasOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Richardson, Texas Office Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_RichardsonTexasOfficeBuildingMember" xlink:href="good-20221231.xsd#good_RichardsonTexasOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_RichardsonTexasOfficeBuildingMember" xlink:to="lab_good_RichardsonTexasOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_DecaturGeorgiaOfficeBuildingTwoMember_21f5c573-c455-41db-ac8f-fc77716e1eb5_terseLabel_en-US" xlink:label="lab_good_DecaturGeorgiaOfficeBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Decatur, Georgia Medical Office Building </link:label>

<link:label id="lab_good_DecaturGeorgiaOfficeBuildingTwoMember_label_en-US" xlink:label="lab_good_DecaturGeorgiaOfficeBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Decatur Georgia Office Building Two [Member] </link:label>

<link:label id="lab_good_DecaturGeorgiaOfficeBuildingTwoMember_documentation_en-US" xlink:label="lab_good_DecaturGeorgiaOfficeBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Decatur Georgia office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DecaturGeorgiaOfficeBuildingTwoMember" xlink:href="good-20221231.xsd#good_DecaturGeorgiaOfficeBuildingTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DecaturGeorgiaOfficeBuildingTwoMember" xlink:to="lab_good_DecaturGeorgiaOfficeBuildingTwoMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AssetRetirementObligationLiabilitiesIncurred_358fa294-3d22-4e0d-963e-a8dc50d075dc_terseLabel_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationLiabilitiesIncurred" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase in asset retirement obligation assumed in acquisition </link:label>

<link:label id="lab_us-gaap_AssetRetirementObligationLiabilitiesIncurred_9dc1d69c-1a15-4770-a34e-d433ff244132_verboseLabel_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationLiabilitiesIncurred" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> ARO liabilities accrued in connection with acquisitions </link:label>

<link:label id="lab_us-gaap_AssetRetirementObligationLiabilitiesIncurred_label_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationLiabilitiesIncurred" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset Retirement Obligation, Liabilities Incurred </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetRetirementObligationLiabilitiesIncurred" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetRetirementObligationLiabilitiesIncurred"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetRetirementObligationLiabilitiesIncurred" xlink:to="lab_us-gaap_AssetRetirementObligationLiabilitiesIncurred" xlink:type="arc" order="1"/>

<link:label id="lab_good_LeaseTermAvailableForLease_7e801199-ae39-4630-9ace-6d01498c5de4_terseLabel_en-US" xlink:label="lab_good_LeaseTermAvailableForLease" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Lease Term </link:label>

<link:label id="lab_good_LeaseTermAvailableForLease_label_en-US" xlink:label="lab_good_LeaseTermAvailableForLease" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease Term Available For Lease </link:label>

<link:label id="lab_good_LeaseTermAvailableForLease_documentation_en-US" xlink:label="lab_good_LeaseTermAvailableForLease" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease term available for lease. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_LeaseTermAvailableForLease" xlink:href="good-20221231.xsd#good_LeaseTermAvailableForLease"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_LeaseTermAvailableForLease" xlink:to="lab_good_LeaseTermAvailableForLease" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AccruedRentCurrentAndNoncurrent_da7b4a21-2e83-49d5-b61a-f1b6fe55ff7b_terseLabel_en-US" xlink:label="lab_us-gaap_AccruedRentCurrentAndNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred rent liability, net </link:label>

<link:label id="lab_us-gaap_AccruedRentCurrentAndNoncurrent_label_en-US" xlink:label="lab_us-gaap_AccruedRentCurrentAndNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued Rent </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedRentCurrentAndNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccruedRentCurrentAndNoncurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccruedRentCurrentAndNoncurrent" xlink:to="lab_us-gaap_AccruedRentCurrentAndNoncurrent" xlink:type="arc" order="1"/>

<link:label id="lab_good_DuncanSouthCarolinaIndustrialBuildingMember_2bbb22be-52f7-4eef-9561-b52f742d7d24_terseLabel_en-US" xlink:label="lab_good_DuncanSouthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Duncan, South Carolina Industrial Building </link:label>

<link:label id="lab_good_DuncanSouthCarolinaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_DuncanSouthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Duncan South Carolina Industrial Building [Member] </link:label>

<link:label id="lab_good_DuncanSouthCarolinaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_DuncanSouthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Duncan South Carolina Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DuncanSouthCarolinaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_DuncanSouthCarolinaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DuncanSouthCarolinaIndustrialBuildingMember" xlink:to="lab_good_DuncanSouthCarolinaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_TerminationFeePayableasPercentageofAverageAnnualManagementFeeandIncentiveFeeDuringTwentyFourMonthPeriod_db0a4e9e-98e2-43dd-93e0-ea51e56ecefd_terseLabel_en-US" xlink:label="lab_good_TerminationFeePayableasPercentageofAverageAnnualManagementFeeandIncentiveFeeDuringTwentyFourMonthPeriod" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Termination fee payable </link:label>

<link:label id="lab_good_TerminationFeePayableasPercentageofAverageAnnualManagementFeeandIncentiveFeeDuringTwentyFourMonthPeriod_label_en-US" xlink:label="lab_good_TerminationFeePayableasPercentageofAverageAnnualManagementFeeandIncentiveFeeDuringTwentyFourMonthPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Termination Fee Payable as Percentage of Average Annual Management Fee and Incentive Fee During Twenty-Four Month Period </link:label>

<link:label id="lab_good_TerminationFeePayableasPercentageofAverageAnnualManagementFeeandIncentiveFeeDuringTwentyFourMonthPeriod_documentation_en-US" xlink:label="lab_good_TerminationFeePayableasPercentageofAverageAnnualManagementFeeandIncentiveFeeDuringTwentyFourMonthPeriod" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Termination Fee Payable, Percentage of Average Annual Management Fee and Incentive Fee During Twenty-Four Month Period </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_TerminationFeePayableasPercentageofAverageAnnualManagementFeeandIncentiveFeeDuringTwentyFourMonthPeriod" xlink:href="good-20221231.xsd#good_TerminationFeePayableasPercentageofAverageAnnualManagementFeeandIncentiveFeeDuringTwentyFourMonthPeriod"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_TerminationFeePayableasPercentageofAverageAnnualManagementFeeandIncentiveFeeDuringTwentyFourMonthPeriod" xlink:to="lab_good_TerminationFeePayableasPercentageofAverageAnnualManagementFeeandIncentiveFeeDuringTwentyFourMonthPeriod" xlink:type="arc" order="1"/>

<link:label id="lab_good_SubsidiariesOneMember_83468e27-5654-4f76-93a1-4816437a1ef2_terseLabel_en-US" xlink:label="lab_good_SubsidiariesOneMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> GCLP Business Trust II </link:label>

<link:label id="lab_good_SubsidiariesOneMember_label_en-US" xlink:label="lab_good_SubsidiariesOneMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsidiaries One [Member] </link:label>

<link:label id="lab_good_SubsidiariesOneMember_documentation_en-US" xlink:label="lab_good_SubsidiariesOneMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsidiaries one. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SubsidiariesOneMember" xlink:href="good-20221231.xsd#good_SubsidiariesOneMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SubsidiariesOneMember" xlink:to="lab_good_SubsidiariesOneMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_CarrolltonGeorgiaIndustrialBuildingMember_eb7f88b3-cb07-4a89-9f51-a7b0915d99e3_terseLabel_en-US" xlink:label="lab_good_CarrolltonGeorgiaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Carrollton, Georgia Industrial Building </link:label>

<link:label id="lab_good_CarrolltonGeorgiaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_CarrolltonGeorgiaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Carrollton, Georgia Industrial Building [Member] </link:label>

<link:label id="lab_good_CarrolltonGeorgiaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_CarrolltonGeorgiaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Carrollton, Georgia Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CarrolltonGeorgiaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_CarrolltonGeorgiaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CarrolltonGeorgiaIndustrialBuildingMember" xlink:to="lab_good_CarrolltonGeorgiaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_AnnualizedIncentiveFeePerAdvisoryAgreement_2de40f1e-197f-4537-8f49-8d8a47bff53e_terseLabel_en-US" xlink:label="lab_good_AnnualizedIncentiveFeePerAdvisoryAgreement" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pre-incentive annual fee FFO in percentage of common stockholders' equity that will reward the adviser </link:label>

<link:label id="lab_good_AnnualizedIncentiveFeePerAdvisoryAgreement_label_en-US" xlink:label="lab_good_AnnualizedIncentiveFeePerAdvisoryAgreement" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Annualized Incentive Fee Per Advisory Agreement </link:label>

<link:label id="lab_good_AnnualizedIncentiveFeePerAdvisoryAgreement_documentation_en-US" xlink:label="lab_good_AnnualizedIncentiveFeePerAdvisoryAgreement" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Annualized incentive fee per advisory agreement. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AnnualizedIncentiveFeePerAdvisoryAgreement" xlink:href="good-20221231.xsd#good_AnnualizedIncentiveFeePerAdvisoryAgreement"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AnnualizedIncentiveFeePerAdvisoryAgreement" xlink:to="lab_good_AnnualizedIncentiveFeePerAdvisoryAgreement" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_794ace09-e946-465f-9b8d-0cffed1124cf_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] </link:label>

<link:label id="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:to="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AboveMarketLeasesMember_d02e1c52-58ec-4764-af26-4bcc51dd8db1_terseLabel_en-US" xlink:label="lab_us-gaap_AboveMarketLeasesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Above Market Leases </link:label>

<link:label id="lab_us-gaap_AboveMarketLeasesMember_label_en-US" xlink:label="lab_us-gaap_AboveMarketLeasesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Above Market Leases [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AboveMarketLeasesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AboveMarketLeasesMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AboveMarketLeasesMember" xlink:to="lab_us-gaap_AboveMarketLeasesMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_ClevelandOhioAndFortPayneAlabamaMember_7d800b55-2a77-43f9-94a3-dedfae289fd1_terseLabel_en-US" xlink:label="lab_good_ClevelandOhioAndFortPayneAlabamaMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cleveland, Ohio And Fort Payne, Alabama </link:label>

<link:label id="lab_good_ClevelandOhioAndFortPayneAlabamaMember_label_en-US" xlink:label="lab_good_ClevelandOhioAndFortPayneAlabamaMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cleveland, Ohio And Fort Payne, Alabama [Member] </link:label>

<link:label id="lab_good_ClevelandOhioAndFortPayneAlabamaMember_documentation_en-US" xlink:label="lab_good_ClevelandOhioAndFortPayneAlabamaMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cleveland, Ohio And Fort Payne, Alabama </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ClevelandOhioAndFortPayneAlabamaMember" xlink:href="good-20221231.xsd#good_ClevelandOhioAndFortPayneAlabamaMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ClevelandOhioAndFortPayneAlabamaMember" xlink:to="lab_good_ClevelandOhioAndFortPayneAlabamaMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_SeriesDEAndGPreferredStockMember_699ae228-0bce-49fd-be05-8289def435c8_terseLabel_en-US" xlink:label="lab_good_SeriesDEAndGPreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series D, E And G Preferred Stock </link:label>

<link:label id="lab_good_SeriesDEAndGPreferredStockMember_label_en-US" xlink:label="lab_good_SeriesDEAndGPreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series D, E And G Preferred Stock [Member] </link:label>

<link:label id="lab_good_SeriesDEAndGPreferredStockMember_documentation_en-US" xlink:label="lab_good_SeriesDEAndGPreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series D, E And G Preferred Stock </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SeriesDEAndGPreferredStockMember" xlink:href="good-20221231.xsd#good_SeriesDEAndGPreferredStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SeriesDEAndGPreferredStockMember" xlink:to="lab_good_SeriesDEAndGPreferredStockMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_PeruIllinoisMember_036ad00a-b925-4992-8b27-a7d6e0b55b40_terseLabel_en-US" xlink:label="lab_good_PeruIllinoisMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Peru, Illinois </link:label>

<link:label id="lab_good_PeruIllinoisMember_label_en-US" xlink:label="lab_good_PeruIllinoisMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Peru, Illinois [Member] </link:label>

<link:label id="lab_good_PeruIllinoisMember_documentation_en-US" xlink:label="lab_good_PeruIllinoisMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Peru, Illinois </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PeruIllinoisMember" xlink:href="good-20221231.xsd#good_PeruIllinoisMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PeruIllinoisMember" xlink:to="lab_good_PeruIllinoisMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_Liabilities_2dd26f12-6356-4d8c-80e8-388638b79281_totalLabel_en-US" xlink:label="lab_us-gaap_Liabilities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> TOTAL LIABILITIES </link:label>

<link:label id="lab_us-gaap_Liabilities_label_en-US" xlink:label="lab_us-gaap_Liabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liabilities </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Liabilities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Liabilities" xlink:to="lab_us-gaap_Liabilities" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_774a771d-423b-43f3-9894-023fd4ee3a26_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted average lease term </link:label>

<link:label id="lab_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Lease, Weighted Average Remaining Lease Term </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:to="lab_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:type="arc" order="1"/>

<link:label id="lab_good_PaymentOfFinancingFee_7f3b3ce2-61bc-43dc-8d24-f695f064e2df_terseLabel_en-US" xlink:label="lab_good_PaymentOfFinancingFee" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fees paid </link:label>

<link:label id="lab_good_PaymentOfFinancingFee_label_en-US" xlink:label="lab_good_PaymentOfFinancingFee" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payment Of Financing Fee </link:label>

<link:label id="lab_good_PaymentOfFinancingFee_documentation_en-US" xlink:label="lab_good_PaymentOfFinancingFee" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payment of financing fee. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PaymentOfFinancingFee" xlink:href="good-20221231.xsd#good_PaymentOfFinancingFee"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PaymentOfFinancingFee" xlink:to="lab_good_PaymentOfFinancingFee" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_84cd486f-f212-44c9-9e50-b91237556fb2_terseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash flows from investing activities: </link:label>

<link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Cash Provided by (Used in) Investing Activities [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_SeniorCommonStockSharesIssued_69bbcbaf-e0e4-4df5-978a-6f4662d8a128_terseLabel_en-US" xlink:label="lab_good_SeniorCommonStockSharesIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior common stock, shares issued (in shares) </link:label>

<link:label id="lab_good_SeniorCommonStockSharesIssued_label_en-US" xlink:label="lab_good_SeniorCommonStockSharesIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior Common Stock Shares Issued </link:label>

<link:label id="lab_good_SeniorCommonStockSharesIssued_documentation_en-US" xlink:label="lab_good_SeniorCommonStockSharesIssued" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior common stock, shares issued. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SeniorCommonStockSharesIssued" xlink:href="good-20221231.xsd#good_SeniorCommonStockSharesIssued"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SeniorCommonStockSharesIssued" xlink:to="lab_good_SeniorCommonStockSharesIssued" xlink:type="arc" order="1"/>

<link:label id="lab_good_DuncanSouthCarolinaIndustrialBuildingOneMember_3f4125a7-bb9b-43ec-8b9c-422f4ce5c5b2_terseLabel_en-US" xlink:label="lab_good_DuncanSouthCarolinaIndustrialBuildingOneMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Duncan, South Carolina Industrial Building </link:label>

<link:label id="lab_good_DuncanSouthCarolinaIndustrialBuildingOneMember_label_en-US" xlink:label="lab_good_DuncanSouthCarolinaIndustrialBuildingOneMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Duncan South Carolina Industrial Building One [Member] </link:label>

<link:label id="lab_good_DuncanSouthCarolinaIndustrialBuildingOneMember_documentation_en-US" xlink:label="lab_good_DuncanSouthCarolinaIndustrialBuildingOneMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Duncan South Carolina Industrial Building One [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DuncanSouthCarolinaIndustrialBuildingOneMember" xlink:href="good-20221231.xsd#good_DuncanSouthCarolinaIndustrialBuildingOneMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DuncanSouthCarolinaIndustrialBuildingOneMember" xlink:to="lab_good_DuncanSouthCarolinaIndustrialBuildingOneMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityCommonStockSharesOutstanding_0ac93e96-0b31-4567-8aa1-8b95b272bd94_terseLabel_en-US" xlink:label="lab_dei_EntityCommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Common Stock, Shares Outstanding </link:label>

<link:label id="lab_dei_EntityCommonStockSharesOutstanding_label_en-US" xlink:label="lab_dei_EntityCommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Common Stock, Shares Outstanding </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityCommonStockSharesOutstanding"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityCommonStockSharesOutstanding" xlink:to="lab_dei_EntityCommonStockSharesOutstanding" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RevolvingCreditFacilityMember_c2798f35-4d9d-433e-9729-9fd3bd573a70_terseLabel_en-US" xlink:label="lab_us-gaap_RevolvingCreditFacilityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revolving credit facility </link:label>

<link:label id="lab_us-gaap_RevolvingCreditFacilityMember_label_en-US" xlink:label="lab_us-gaap_RevolvingCreditFacilityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revolving Credit Facility [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevolvingCreditFacilityMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevolvingCreditFacilityMember" xlink:to="lab_us-gaap_RevolvingCreditFacilityMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_DocumentType_d6c711f6-20c0-435b-9a46-7484d57fad8c_terseLabel_en-US" xlink:label="lab_dei_DocumentType" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Type </link:label>

<link:label id="lab_dei_DocumentType_label_en-US" xlink:label="lab_dei_DocumentType" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Type </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentType"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentType" xlink:to="lab_dei_DocumentType" xlink:type="arc" order="1"/>

<link:label id="lab_good_TiftonGeorgiaIndustrialBuildingMember_e556cb96-1368-4cdf-a4b2-a138a72a8b80_terseLabel_en-US" xlink:label="lab_good_TiftonGeorgiaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tifton, Georgia Industrial Building </link:label>

<link:label id="lab_good_TiftonGeorgiaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_TiftonGeorgiaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tifton, Georgia Industrial Building [Member] </link:label>

<link:label id="lab_good_TiftonGeorgiaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_TiftonGeorgiaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tifton, Georgia Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_TiftonGeorgiaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_TiftonGeorgiaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_TiftonGeorgiaIndustrialBuildingMember" xlink:to="lab_good_TiftonGeorgiaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_539ea266-ae79-46c6-a4f7-c9aaa091f036_terseLabel_en-US" xlink:label="lab_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate </link:label>

<link:label id="lab_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_label_en-US" xlink:label="lab_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember" xlink:to="lab_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife_9b21067f-51aa-4aa6-a429-67b230c0de6c_verboseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Estimated useful life </link:label>

<link:label id="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife_59c7a3c6-3165-4863-a06e-e57b61fdfd48_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Depreciable life </link:label>

<link:label id="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment, Useful Life </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_2d0261ea-b5dc-45b6-9972-70f81b528879_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets, Major Class Name [Domain] </link:label>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets, Major Class Name [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:type="arc" order="1"/>

<link:label id="lab_good_PacificMissouriIndustrialBuildingMember_485f5f33-458e-41b3-bab2-cf912dae101a_terseLabel_en-US" xlink:label="lab_good_PacificMissouriIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pacific, Missouri Industrial Building </link:label>

<link:label id="lab_good_PacificMissouriIndustrialBuildingMember_label_en-US" xlink:label="lab_good_PacificMissouriIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pacific, Missouri Industrial Building [Member] </link:label>

<link:label id="lab_good_PacificMissouriIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_PacificMissouriIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pacific, Missouri Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PacificMissouriIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_PacificMissouriIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PacificMissouriIndustrialBuildingMember" xlink:to="lab_good_PacificMissouriIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_DealerManagementAgreementMember_7318c0f9-bce6-45ea-87b6-d15a94064898_terseLabel_en-US" xlink:label="lab_good_DealerManagementAgreementMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dealer Management Agreement </link:label>

<link:label id="lab_good_DealerManagementAgreementMember_label_en-US" xlink:label="lab_good_DealerManagementAgreementMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dealer Management Agreement [Member] </link:label>

<link:label id="lab_good_DealerManagementAgreementMember_documentation_en-US" xlink:label="lab_good_DealerManagementAgreementMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dealer Management Agreement [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DealerManagementAgreementMember" xlink:href="good-20221231.xsd#good_DealerManagementAgreementMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DealerManagementAgreementMember" xlink:to="lab_good_DealerManagementAgreementMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_ColumbusOhioOfficeBuildingTwoMember_c6633e79-7236-47a3-b6ef-4ce7ece64035_terseLabel_en-US" xlink:label="lab_good_ColumbusOhioOfficeBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbus Ohio Office Building Two </link:label>

<link:label id="lab_good_ColumbusOhioOfficeBuildingTwoMember_label_en-US" xlink:label="lab_good_ColumbusOhioOfficeBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbus Ohio Office Building Two [Member] </link:label>

<link:label id="lab_good_ColumbusOhioOfficeBuildingTwoMember_documentation_en-US" xlink:label="lab_good_ColumbusOhioOfficeBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbus Ohio Office Building Two [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ColumbusOhioOfficeBuildingTwoMember" xlink:href="good-20221231.xsd#good_ColumbusOhioOfficeBuildingTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ColumbusOhioOfficeBuildingTwoMember" xlink:to="lab_good_ColumbusOhioOfficeBuildingTwoMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_PreferredStockSharesAuthorizedDividendReinvestmentPlan_ca251fb9-2cfe-428d-b70a-4428553a29be_terseLabel_en-US" xlink:label="lab_good_PreferredStockSharesAuthorizedDividendReinvestmentPlan" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Redeemable preferred stock, dividend reinvestment plan, shares authorized (in shares) </link:label>

<link:label id="lab_good_PreferredStockSharesAuthorizedDividendReinvestmentPlan_label_en-US" xlink:label="lab_good_PreferredStockSharesAuthorizedDividendReinvestmentPlan" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred Stock, Shares Authorized, Dividend Reinvestment Plan </link:label>

<link:label id="lab_good_PreferredStockSharesAuthorizedDividendReinvestmentPlan_documentation_en-US" xlink:label="lab_good_PreferredStockSharesAuthorizedDividendReinvestmentPlan" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred Stock, Shares Authorized, Dividend Reinvestment Plan </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PreferredStockSharesAuthorizedDividendReinvestmentPlan" xlink:href="good-20221231.xsd#good_PreferredStockSharesAuthorizedDividendReinvestmentPlan"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PreferredStockSharesAuthorizedDividendReinvestmentPlan" xlink:to="lab_good_PreferredStockSharesAuthorizedDividendReinvestmentPlan" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberofQuartersUsedfortheCapofAverageQuarterlyIncentiveFees_0addf64a-e23b-456f-beca-8df249022684_terseLabel_en-US" xlink:label="lab_good_NumberofQuartersUsedfortheCapofAverageQuarterlyIncentiveFees" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of quarters used for the cap of average quarterly incentive fees </link:label>

<link:label id="lab_good_NumberofQuartersUsedfortheCapofAverageQuarterlyIncentiveFees_label_en-US" xlink:label="lab_good_NumberofQuartersUsedfortheCapofAverageQuarterlyIncentiveFees" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Quarters Used for the Cap of Average Quarterly Incentive Fees </link:label>

<link:label id="lab_good_NumberofQuartersUsedfortheCapofAverageQuarterlyIncentiveFees_documentation_en-US" xlink:label="lab_good_NumberofQuartersUsedfortheCapofAverageQuarterlyIncentiveFees" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Quarters Used for the Cap of Average Quarterly Incentive Fees </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberofQuartersUsedfortheCapofAverageQuarterlyIncentiveFees" xlink:href="good-20221231.xsd#good_NumberofQuartersUsedfortheCapofAverageQuarterlyIncentiveFees"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberofQuartersUsedfortheCapofAverageQuarterlyIncentiveFees" xlink:to="lab_good_NumberofQuartersUsedfortheCapofAverageQuarterlyIncentiveFees" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_eff1706f-0e26-4ab3-8943-7c9435563823_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Instruments, Gain (Loss) [Table] </link:label>

<link:label id="lab_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_label_en-US" xlink:label="lab_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Instruments, Gain (Loss) [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" xlink:to="lab_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DebtDisclosureAbstract_186dc57a-6470-444f-9ea3-a9df9fa8e21d_terseLabel_en-US" xlink:label="lab_us-gaap_DebtDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Disclosure [Abstract] </link:label>

<link:label id="lab_us-gaap_DebtDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_DebtDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Disclosure [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtDisclosureAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtDisclosureAbstract" xlink:to="lab_us-gaap_DebtDisclosureAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_CummingGeorgiaOfficeBuildingMember_0baba9d0-e6a8-481e-be13-303a35031945_terseLabel_en-US" xlink:label="lab_good_CummingGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cumming, Georgia Medical Office Building </link:label>

<link:label id="lab_good_CummingGeorgiaOfficeBuildingMember_label_en-US" xlink:label="lab_good_CummingGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cumming Georgia Office Building [Member] </link:label>

<link:label id="lab_good_CummingGeorgiaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_CummingGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cumming Georgia office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CummingGeorgiaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_CummingGeorgiaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CummingGeorgiaOfficeBuildingMember" xlink:to="lab_good_CummingGeorgiaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_IncomeStatementLocationAxis_e7a06bc5-7ea8-4577-9fba-8f5021e7f671_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeStatementLocationAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Statement Location [Axis] </link:label>

<link:label id="lab_us-gaap_IncomeStatementLocationAxis_label_en-US" xlink:label="lab_us-gaap_IncomeStatementLocationAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Statement Location [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeStatementLocationAxis" xlink:to="lab_us-gaap_IncomeStatementLocationAxis" xlink:type="arc" order="1"/>

<link:label id="lab_good_PropertyOperatingExpenses_a923f083-f49b-4621-a1d5-f4f68e5379ba_terseLabel_en-US" xlink:label="lab_good_PropertyOperatingExpenses" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property operating expenses </link:label>

<link:label id="lab_good_PropertyOperatingExpenses_label_en-US" xlink:label="lab_good_PropertyOperatingExpenses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property Operating Expenses </link:label>

<link:label id="lab_good_PropertyOperatingExpenses_documentation_en-US" xlink:label="lab_good_PropertyOperatingExpenses" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property Operating Expenses </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PropertyOperatingExpenses" xlink:href="good-20221231.xsd#good_PropertyOperatingExpenses"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PropertyOperatingExpenses" xlink:to="lab_good_PropertyOperatingExpenses" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities_ce74d1f1-acab-475f-8901-fff0e89c3517_totalLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net cash provided by financing activities </link:label>

<link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Cash Provided by (Used in) Financing Activities </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:type="arc" order="1"/>

<link:label id="lab_good_ScheduleOfRealEstateOwnedHeldForSaleTable_400a131e-3923-4d69-81bc-3936aa8cb1e6_terseLabel_en-US" xlink:label="lab_good_ScheduleOfRealEstateOwnedHeldForSaleTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Real Estate Owned Held For Sale [Table] </link:label>

<link:label id="lab_good_ScheduleOfRealEstateOwnedHeldForSaleTable_label_en-US" xlink:label="lab_good_ScheduleOfRealEstateOwnedHeldForSaleTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Real Estate Owned Held For Sale [Table] </link:label>

<link:label id="lab_good_ScheduleOfRealEstateOwnedHeldForSaleTable_documentation_en-US" xlink:label="lab_good_ScheduleOfRealEstateOwnedHeldForSaleTable" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of real estate owned held for sale. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ScheduleOfRealEstateOwnedHeldForSaleTable" xlink:href="good-20221231.xsd#good_ScheduleOfRealEstateOwnedHeldForSaleTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ScheduleOfRealEstateOwnedHeldForSaleTable" xlink:to="lab_good_ScheduleOfRealEstateOwnedHeldForSaleTable" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LineOfCreditMember_6bcd770f-da53-40f8-aa95-9b9d546f65e5_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of credit </link:label>

<link:label id="lab_us-gaap_LineOfCreditMember_label_en-US" xlink:label="lab_us-gaap_LineOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of Credit [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditMember" xlink:to="lab_us-gaap_LineOfCreditMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_VariableLeaseCost_4269a7f5-77c7-481d-a9e6-f10f8e46ad26_terseLabel_en-US" xlink:label="lab_us-gaap_VariableLeaseCost" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable lease payments </link:label>

<link:label id="lab_us-gaap_VariableLeaseCost_label_en-US" xlink:label="lab_us-gaap_VariableLeaseCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Lease, Cost </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableLeaseCost" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableLeaseCost"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_VariableLeaseCost" xlink:to="lab_us-gaap_VariableLeaseCost" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StockholdersEquityAbstract_ce074500-709c-4da8-9ad7-b1d72f2d3976_terseLabel_en-US" xlink:label="lab_us-gaap_StockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> EQUITY </link:label>

<link:label id="lab_us-gaap_StockholdersEquityAbstract_label_en-US" xlink:label="lab_us-gaap_StockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stockholders' Equity Attributable to Parent [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockholdersEquityAbstract" xlink:to="lab_us-gaap_StockholdersEquityAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RelatedPartyTransactionLineItems_ed633d53-11cf-4386-85fa-4e5be6cb7ec4_terseLabel_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Related Party Transaction [Line Items] </link:label>

<link:label id="lab_us-gaap_RelatedPartyTransactionLineItems_label_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Related Party Transaction [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems" xlink:to="lab_us-gaap_RelatedPartyTransactionLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_good_SeniorCommonStockValueIssued_edbbc96c-2735-44a6-80aa-2494999db41d_terseLabel_en-US" xlink:label="lab_good_SeniorCommonStockValueIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior common stock, par value $0.001 per share; 950,000 shares authorized; and 431,064 and 600,061 shares issued and outstanding at December 31, 2022 and December 31, 2021, respectively </link:label>

<link:label id="lab_good_SeniorCommonStockValueIssued_label_en-US" xlink:label="lab_good_SeniorCommonStockValueIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior Common Stock, Value, Issued </link:label>

<link:label id="lab_good_SeniorCommonStockValueIssued_documentation_en-US" xlink:label="lab_good_SeniorCommonStockValueIssued" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior Common Stock, Value, Issued </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SeniorCommonStockValueIssued" xlink:href="good-20221231.xsd#good_SeniorCommonStockValueIssued"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SeniorCommonStockValueIssued" xlink:to="lab_good_SeniorCommonStockValueIssued" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DerivativeContractTypeDomain_5e104851-40e0-4085-a299-8f8dac4a819e_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeContractTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Contract [Domain] </link:label>

<link:label id="lab_us-gaap_DerivativeContractTypeDomain_label_en-US" xlink:label="lab_us-gaap_DerivativeContractTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Contract [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeContractTypeDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeContractTypeDomain" xlink:to="lab_us-gaap_DerivativeContractTypeDomain" xlink:type="arc" order="1"/>

<link:label id="lab_good_BaytownTexasMember_f4ac5c29-8ec1-4713-a215-8b16612b7750_terseLabel_en-US" xlink:label="lab_good_BaytownTexasMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Baytown, Texas </link:label>

<link:label id="lab_good_BaytownTexasMember_label_en-US" xlink:label="lab_good_BaytownTexasMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Baytown, Texas [Member] </link:label>

<link:label id="lab_good_BaytownTexasMember_documentation_en-US" xlink:label="lab_good_BaytownTexasMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Baytown, Texas </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BaytownTexasMember" xlink:href="good-20221231.xsd#good_BaytownTexasMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BaytownTexasMember" xlink:to="lab_good_BaytownTexasMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityRegistrantName_1f68e534-a7eb-4d01-97c7-5b4a00b2d273_terseLabel_en-US" xlink:label="lab_dei_EntityRegistrantName" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Registrant Name </link:label>

<link:label id="lab_dei_EntityRegistrantName_label_en-US" xlink:label="lab_dei_EntityRegistrantName" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Registrant Name </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityRegistrantName"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityRegistrantName" xlink:to="lab_dei_EntityRegistrantName" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StockRedeemedOrCalledDuringPeriodValue_723d0fc6-9c84-4e01-bd29-c4fe78fe444a_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_StockRedeemedOrCalledDuringPeriodValue" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Redemption of preferred stock, net </link:label>

<link:label id="lab_us-gaap_StockRedeemedOrCalledDuringPeriodValue_0f125128-a131-49e2-a42a-fd387f3f7eb1_terseLabel_en-US" xlink:label="lab_us-gaap_StockRedeemedOrCalledDuringPeriodValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock redeemed </link:label>

<link:label id="lab_us-gaap_StockRedeemedOrCalledDuringPeriodValue_label_en-US" xlink:label="lab_us-gaap_StockRedeemedOrCalledDuringPeriodValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Redeemed or Called During Period, Value </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRedeemedOrCalledDuringPeriodValue" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockRedeemedOrCalledDuringPeriodValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockRedeemedOrCalledDuringPeriodValue" xlink:to="lab_us-gaap_StockRedeemedOrCalledDuringPeriodValue" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SubsequentEventsTextBlock_e226233c-1d37-4fd3-819b-9933f6fb6efb_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsequent Events </link:label>

<link:label id="lab_us-gaap_SubsequentEventsTextBlock_label_en-US" xlink:label="lab_us-gaap_SubsequentEventsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsequent Events [Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventsTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventsTextBlock" xlink:to="lab_us-gaap_SubsequentEventsTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent_22a8b85d-7c1d-4da0-9126-a755137e6602_terseLabel_en-US" xlink:label="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts payable and accrued expenses </link:label>

<link:label id="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent_label_en-US" xlink:label="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts Payable and Accrued Liabilities </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent" xlink:to="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent" xlink:type="arc" order="1"/>

<link:label id="lab_good_MariettaOhioIndustrialBuildingMember_30b52271-1797-4657-8d85-9fbe2133da64_terseLabel_en-US" xlink:label="lab_good_MariettaOhioIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Marietta, Ohio Industrial Building </link:label>

<link:label id="lab_good_MariettaOhioIndustrialBuildingMember_label_en-US" xlink:label="lab_good_MariettaOhioIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Marietta Ohio Industrial Building [Member] </link:label>

<link:label id="lab_good_MariettaOhioIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_MariettaOhioIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Marietta Ohio industrial building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_MariettaOhioIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_MariettaOhioIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_MariettaOhioIndustrialBuildingMember" xlink:to="lab_good_MariettaOhioIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_TenantImprovements_2ced5f2f-fd99-443c-b058-02f77757cd84_terseLabel_en-US" xlink:label="lab_us-gaap_TenantImprovements" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tenant improvements </link:label>

<link:label id="lab_us-gaap_TenantImprovements_label_en-US" xlink:label="lab_us-gaap_TenantImprovements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tenant Improvements </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TenantImprovements" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TenantImprovements"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TenantImprovements" xlink:to="lab_us-gaap_TenantImprovements" xlink:type="arc" order="1"/>

<link:label id="lab_good_SanAntonioTexasIndustrialBuildingMember_630cff09-9e48-4927-9c73-e44f505f0868_terseLabel_en-US" xlink:label="lab_good_SanAntonioTexasIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> San Antonio, Texas Industrial Building </link:label>

<link:label id="lab_good_SanAntonioTexasIndustrialBuildingMember_label_en-US" xlink:label="lab_good_SanAntonioTexasIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> San Antonio, Texas Industrial Building [Member] </link:label>

<link:label id="lab_good_SanAntonioTexasIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_SanAntonioTexasIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> San Antonio, Texas Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SanAntonioTexasIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_SanAntonioTexasIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SanAntonioTexasIndustrialBuildingMember" xlink:to="lab_good_SanAntonioTexasIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_DublinOhioOfficeBuildingMember_4b1bd548-dc6a-49ba-ac99-da264d6954b1_terseLabel_en-US" xlink:label="lab_good_DublinOhioOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dublin, Ohio Office Building </link:label>

<link:label id="lab_good_DublinOhioOfficeBuildingMember_label_en-US" xlink:label="lab_good_DublinOhioOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dublin Ohio Office Building [Member] </link:label>

<link:label id="lab_good_DublinOhioOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_DublinOhioOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dublin, Ohio Office Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DublinOhioOfficeBuildingMember" xlink:href="good-20221231.xsd#good_DublinOhioOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DublinOhioOfficeBuildingMember" xlink:to="lab_good_DublinOhioOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstatePropertiesLineItems_25490e79-2e29-46ae-84f6-9090a2539834_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstatePropertiesLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Properties [Line Items] </link:label>

<link:label id="lab_us-gaap_RealEstatePropertiesLineItems_label_en-US" xlink:label="lab_us-gaap_RealEstatePropertiesLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Properties [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstatePropertiesLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstatePropertiesLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstatePropertiesLineItems" xlink:to="lab_us-gaap_RealEstatePropertiesLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_8a095a11-b67f-404d-941c-9ce9206068b0_totalLabel_en-US" xlink:label="lab_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> TOTAL EQUITY </link:label>

<link:label id="lab_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_83f90a16-abf5-4520-a051-9f0f07431205_periodStartLabel_en-US" xlink:label="lab_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Beginning balance </link:label>

<link:label id="lab_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_ec743832-bb27-470f-b690-5409f8b67cde_periodEndLabel_en-US" xlink:label="lab_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ending balance </link:label>

<link:label id="lab_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_label_en-US" xlink:label="lab_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="lab_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ConsolidationPolicyTextBlock_1b6aa78e-9ba7-4e24-8e6e-c10edeee9042_terseLabel_en-US" xlink:label="lab_us-gaap_ConsolidationPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsidiaries </link:label>

<link:label id="lab_us-gaap_ConsolidationPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_ConsolidationPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Consolidation, Policy [Policy Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsolidationPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConsolidationPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConsolidationPolicyTextBlock" xlink:to="lab_us-gaap_ConsolidationPolicyTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_PittsburghPennsylvaniaOfficeBuildingMember_1f99dc2f-dba8-4757-bc2f-ecefa90fb0e3_terseLabel_en-US" xlink:label="lab_good_PittsburghPennsylvaniaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pittsburgh, Pennsylvania Office Building </link:label>

<link:label id="lab_good_PittsburghPennsylvaniaOfficeBuildingMember_label_en-US" xlink:label="lab_good_PittsburghPennsylvaniaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pittsburgh Pennsylvania Office Building [Member] </link:label>

<link:label id="lab_good_PittsburghPennsylvaniaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_PittsburghPennsylvaniaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pittsburgh Pennsylvania office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PittsburghPennsylvaniaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_PittsburghPennsylvaniaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PittsburghPennsylvaniaOfficeBuildingMember" xlink:to="lab_good_PittsburghPennsylvaniaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_srt_MinimumMember_1662fc3d-f7d7-4464-95fc-9af30d65bff5_terseLabel_en-US" xlink:label="lab_srt_MinimumMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Minimum </link:label>

<link:label id="lab_srt_MinimumMember_label_en-US" xlink:label="lab_srt_MinimumMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Minimum [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MinimumMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_MinimumMember" xlink:to="lab_srt_MinimumMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_DividendDeclaredPeriodThreeMember_d85692d1-0b38-4efd-86e3-f50388afb711_terseLabel_en-US" xlink:label="lab_good_DividendDeclaredPeriodThreeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividend Declared, Period Three </link:label>

<link:label id="lab_good_DividendDeclaredPeriodThreeMember_label_en-US" xlink:label="lab_good_DividendDeclaredPeriodThreeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividend Declared, Period Three [Member] </link:label>

<link:label id="lab_good_DividendDeclaredPeriodThreeMember_documentation_en-US" xlink:label="lab_good_DividendDeclaredPeriodThreeMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividend Declared, Period Three [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DividendDeclaredPeriodThreeMember" xlink:href="good-20221231.xsd#good_DividendDeclaredPeriodThreeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DividendDeclaredPeriodThreeMember" xlink:to="lab_good_DividendDeclaredPeriodThreeMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_PacificMissouriIndustrialBuildingThreeMember_b1e1dfb5-a545-4af4-8287-694db025eb19_terseLabel_en-US" xlink:label="lab_good_PacificMissouriIndustrialBuildingThreeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pacific, Missouri Industrial Building Three </link:label>

<link:label id="lab_good_PacificMissouriIndustrialBuildingThreeMember_label_en-US" xlink:label="lab_good_PacificMissouriIndustrialBuildingThreeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pacific, Missouri Industrial Building Three [Member] </link:label>

<link:label id="lab_good_PacificMissouriIndustrialBuildingThreeMember_documentation_en-US" xlink:label="lab_good_PacificMissouriIndustrialBuildingThreeMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pacific, Missouri Industrial Building Three </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PacificMissouriIndustrialBuildingThreeMember" xlink:href="good-20221231.xsd#good_PacificMissouriIndustrialBuildingThreeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PacificMissouriIndustrialBuildingThreeMember" xlink:to="lab_good_PacificMissouriIndustrialBuildingThreeMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityEmergingGrowthCompany_742f6a04-6323-4f15-bb22-226209300249_terseLabel_en-US" xlink:label="lab_dei_EntityEmergingGrowthCompany" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Emerging Growth Company </link:label>

<link:label id="lab_dei_EntityEmergingGrowthCompany_label_en-US" xlink:label="lab_dei_EntityEmergingGrowthCompany" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Emerging Growth Company </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityEmergingGrowthCompany"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityEmergingGrowthCompany" xlink:to="lab_dei_EntityEmergingGrowthCompany" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CommonStockParOrStatedValuePerShare_2c90c924-8481-402b-b1e0-2b6335e767b4_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockParOrStatedValuePerShare" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common stock, par value (in dollars per share) </link:label>

<link:label id="lab_us-gaap_CommonStockParOrStatedValuePerShare_label_en-US" xlink:label="lab_us-gaap_CommonStockParOrStatedValuePerShare" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock, Par or Stated Value Per Share </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockParOrStatedValuePerShare" xlink:to="lab_us-gaap_CommonStockParOrStatedValuePerShare" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DerivativeCostOfHedge_88952058-4f4b-4c82-bcfc-fd39158448c0_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeCostOfHedge" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate Cost </link:label>

<link:label id="lab_us-gaap_DerivativeCostOfHedge_label_en-US" xlink:label="lab_us-gaap_DerivativeCostOfHedge" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative, Cost of Hedge </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeCostOfHedge" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeCostOfHedge"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeCostOfHedge" xlink:to="lab_us-gaap_DerivativeCostOfHedge" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_a084d5b1-d56e-4f21-bd44-b9c0716c43ef_terseLabel_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commitments and Contingencies Disclosure [Abstract] </link:label>

<link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commitments and Contingencies Disclosure [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_dei_TradingSymbol_90b2c4c1-6c56-426f-bae2-01d724f4a5d2_terseLabel_en-US" xlink:label="lab_dei_TradingSymbol" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Trading Symbol </link:label>

<link:label id="lab_dei_TradingSymbol_label_en-US" xlink:label="lab_dei_TradingSymbol" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Trading Symbol </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_TradingSymbol"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_TradingSymbol" xlink:to="lab_dei_TradingSymbol" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityFileNumber_c32a9788-9229-4bdc-9257-64db978bfc17_terseLabel_en-US" xlink:label="lab_dei_EntityFileNumber" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity File Number </link:label>

<link:label id="lab_dei_EntityFileNumber_label_en-US" xlink:label="lab_dei_EntityFileNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity File Number </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityFileNumber"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityFileNumber" xlink:to="lab_dei_EntityFileNumber" xlink:type="arc" order="1"/>

<link:label id="lab_good_OperatingExpensesBeforeIncentiveFeeCredit_5c49a258-33b0-4587-a7d0-8f983e34b9ac_totalLabel_en-US" xlink:label="lab_good_OperatingExpensesBeforeIncentiveFeeCredit" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total operating expense before incentive fee waiver </link:label>

<link:label id="lab_good_OperatingExpensesBeforeIncentiveFeeCredit_label_en-US" xlink:label="lab_good_OperatingExpensesBeforeIncentiveFeeCredit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Expenses Before Incentive Fee Credit </link:label>

<link:label id="lab_good_OperatingExpensesBeforeIncentiveFeeCredit_documentation_en-US" xlink:label="lab_good_OperatingExpensesBeforeIncentiveFeeCredit" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Expenses Before Incentive Fee Credit </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_OperatingExpensesBeforeIncentiveFeeCredit" xlink:href="good-20221231.xsd#good_OperatingExpensesBeforeIncentiveFeeCredit"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_OperatingExpensesBeforeIncentiveFeeCredit" xlink:to="lab_good_OperatingExpensesBeforeIncentiveFeeCredit" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_b5dbb65a-cd13-40dc-8269-c0ede2f0904a_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2026 </link:label>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Asset, Expected Amortization, Year Four </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AccumulatedDistributionsInExcessOfNetIncomeMember_1869caa6-38fc-43f7-8323-0b6a25f463b5_terseLabel_en-US" xlink:label="lab_us-gaap_AccumulatedDistributionsInExcessOfNetIncomeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Distributions in Excess of Accumulated Earnings </link:label>

<link:label id="lab_us-gaap_AccumulatedDistributionsInExcessOfNetIncomeMember_label_en-US" xlink:label="lab_us-gaap_AccumulatedDistributionsInExcessOfNetIncomeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accumulated Distributions in Excess of Net Income [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDistributionsInExcessOfNetIncomeMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedDistributionsInExcessOfNetIncomeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccumulatedDistributionsInExcessOfNetIncomeMember" xlink:to="lab_us-gaap_AccumulatedDistributionsInExcessOfNetIncomeMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest_c95a7c83-0b86-4c63-a4a1-19056b1be75c_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Comprehensive loss (income) attributable (available) to OP Units held by Non-controlling OP Unitholders </link:label>

<link:label id="lab_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest_label_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest" xlink:to="lab_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest" xlink:type="arc" order="1"/>

<link:label id="lab_good_BairdGoldmanSachsStifelFifthThirdAndUSBancorpInvestmentsIncMember_20507fb3-e291-47cd-8768-883cd941b582_terseLabel_en-US" xlink:label="lab_good_BairdGoldmanSachsStifelFifthThirdAndUSBancorpInvestmentsIncMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Baird, Goldman Sachs, Stifel, Fifth Third, and U.S. Bancorp Investments, Inc. </link:label>

<link:label id="lab_good_BairdGoldmanSachsStifelFifthThirdAndUSBancorpInvestmentsIncMember_label_en-US" xlink:label="lab_good_BairdGoldmanSachsStifelFifthThirdAndUSBancorpInvestmentsIncMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Baird, Goldman Sachs, Stifel, Fifth Third, and U.S. Bancorp Investments, Inc. [Member] </link:label>

<link:label id="lab_good_BairdGoldmanSachsStifelFifthThirdAndUSBancorpInvestmentsIncMember_documentation_en-US" xlink:label="lab_good_BairdGoldmanSachsStifelFifthThirdAndUSBancorpInvestmentsIncMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Baird, Goldman Sachs, Stifel, Fifth Third, and U.S. Bancorp Investments, Inc. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BairdGoldmanSachsStifelFifthThirdAndUSBancorpInvestmentsIncMember" xlink:href="good-20221231.xsd#good_BairdGoldmanSachsStifelFifthThirdAndUSBancorpInvestmentsIncMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BairdGoldmanSachsStifelFifthThirdAndUSBancorpInvestmentsIncMember" xlink:to="lab_good_BairdGoldmanSachsStifelFifthThirdAndUSBancorpInvestmentsIncMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_ReadingPennsylvaniaIndustrialBuildingMember_6cac3dc8-3b6f-4328-8cb7-34d694d2efe4_terseLabel_en-US" xlink:label="lab_good_ReadingPennsylvaniaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reading, Pennsylvania Industrial Building </link:label>

<link:label id="lab_good_ReadingPennsylvaniaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_ReadingPennsylvaniaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reading Pennsylvania Industrial Building [Member] </link:label>

<link:label id="lab_good_ReadingPennsylvaniaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_ReadingPennsylvaniaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reading Pennsylvania industrial building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ReadingPennsylvaniaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_ReadingPennsylvaniaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ReadingPennsylvaniaIndustrialBuildingMember" xlink:to="lab_good_ReadingPennsylvaniaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SeriesEPreferredStockMember_06783d65-029e-44ea-9fbe-3b0ceaafef78_terseLabel_en-US" xlink:label="lab_us-gaap_SeriesEPreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series E Preferred Stock </link:label>

<link:label id="lab_us-gaap_SeriesEPreferredStockMember_label_en-US" xlink:label="lab_us-gaap_SeriesEPreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series E Preferred Stock [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesEPreferredStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeriesEPreferredStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SeriesEPreferredStockMember" xlink:to="lab_us-gaap_SeriesEPreferredStockMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ProceedsFromLinesOfCredit_47746736-97c6-40c1-a8e4-087d2dd3258e_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromLinesOfCredit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Borrowings from revolving credit facility </link:label>

<link:label id="lab_us-gaap_ProceedsFromLinesOfCredit_label_en-US" xlink:label="lab_us-gaap_ProceedsFromLinesOfCredit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from Lines of Credit </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromLinesOfCredit" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromLinesOfCredit"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromLinesOfCredit" xlink:to="lab_us-gaap_ProceedsFromLinesOfCredit" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_UseOfEstimates_ae36751b-8f92-42c5-a713-4c3d38cbc5dd_terseLabel_en-US" xlink:label="lab_us-gaap_UseOfEstimates" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Use of Estimates </link:label>

<link:label id="lab_us-gaap_UseOfEstimates_label_en-US" xlink:label="lab_us-gaap_UseOfEstimates" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Use of Estimates, Policy [Policy Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_UseOfEstimates" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_UseOfEstimates"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_UseOfEstimates" xlink:to="lab_us-gaap_UseOfEstimates" xlink:type="arc" order="1"/>

<link:label id="lab_good_StockIssuanceCostPolicyPolicyTextBlock_a1ae45c1-639e-4bba-abca-2f41675916d1_terseLabel_en-US" xlink:label="lab_good_StockIssuanceCostPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Issuance Costs </link:label>

<link:label id="lab_good_StockIssuanceCostPolicyPolicyTextBlock_label_en-US" xlink:label="lab_good_StockIssuanceCostPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Issuance Cost Policy [Policy Text Block] </link:label>

<link:label id="lab_good_StockIssuanceCostPolicyPolicyTextBlock_documentation_en-US" xlink:label="lab_good_StockIssuanceCostPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock issuance cost. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_StockIssuanceCostPolicyPolicyTextBlock" xlink:href="good-20221231.xsd#good_StockIssuanceCostPolicyPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_StockIssuanceCostPolicyPolicyTextBlock" xlink:to="lab_good_StockIssuanceCostPolicyPolicyTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_DividendDeclaredPeriodTwoMember_6edc81ca-f652-457a-b45e-b8ae09ae544e_terseLabel_en-US" xlink:label="lab_good_DividendDeclaredPeriodTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividend Declared, Period Two </link:label>

<link:label id="lab_good_DividendDeclaredPeriodTwoMember_label_en-US" xlink:label="lab_good_DividendDeclaredPeriodTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividend Declared, Period Two [Member] </link:label>

<link:label id="lab_good_DividendDeclaredPeriodTwoMember_documentation_en-US" xlink:label="lab_good_DividendDeclaredPeriodTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividend Declared, Period Two [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DividendDeclaredPeriodTwoMember" xlink:href="good-20221231.xsd#good_DividendDeclaredPeriodTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DividendDeclaredPeriodTwoMember" xlink:to="lab_good_DividendDeclaredPeriodTwoMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_TempleTexasIndustrialBuildingTwoMember_7933082f-54e9-45cc-b550-adac5ab15300_terseLabel_en-US" xlink:label="lab_good_TempleTexasIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Temple, Texas Industrial Building Two </link:label>

<link:label id="lab_good_TempleTexasIndustrialBuildingTwoMember_label_en-US" xlink:label="lab_good_TempleTexasIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Temple, Texas Industrial Building Two [Member] </link:label>

<link:label id="lab_good_TempleTexasIndustrialBuildingTwoMember_documentation_en-US" xlink:label="lab_good_TempleTexasIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Temple, Texas Industrial Building Two [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_TempleTexasIndustrialBuildingTwoMember" xlink:href="good-20221231.xsd#good_TempleTexasIndustrialBuildingTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_TempleTexasIndustrialBuildingTwoMember" xlink:to="lab_good_TempleTexasIndustrialBuildingTwoMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_NonQualifyingIncomeRelatedToRealEstatePortfolio_01cb2688-53db-4669-8aba-49740278ffa3_terseLabel_en-US" xlink:label="lab_good_NonQualifyingIncomeRelatedToRealEstatePortfolio" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Non-qualifying income related to real estate portfolio </link:label>

<link:label id="lab_good_NonQualifyingIncomeRelatedToRealEstatePortfolio_label_en-US" xlink:label="lab_good_NonQualifyingIncomeRelatedToRealEstatePortfolio" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Non Qualifying Income Related To Real Estate Portfolio </link:label>

<link:label id="lab_good_NonQualifyingIncomeRelatedToRealEstatePortfolio_documentation_en-US" xlink:label="lab_good_NonQualifyingIncomeRelatedToRealEstatePortfolio" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Non qualifying income related to real estate portfolio. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NonQualifyingIncomeRelatedToRealEstatePortfolio" xlink:href="good-20221231.xsd#good_NonQualifyingIncomeRelatedToRealEstatePortfolio"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NonQualifyingIncomeRelatedToRealEstatePortfolio" xlink:to="lab_good_NonQualifyingIncomeRelatedToRealEstatePortfolio" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DebtInstrumentFeeAmount_5a362513-df1c-4807-8c04-8db44a7aba88_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentFeeAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt instrument, fee </link:label>

<link:label id="lab_us-gaap_DebtInstrumentFeeAmount_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentFeeAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Fee Amount </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFeeAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentFeeAmount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentFeeAmount" xlink:to="lab_us-gaap_DebtInstrumentFeeAmount" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_70fbbd74-1468-4943-9a41-56d534135e15_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (decrease) in accounts payable and accrued expenses </link:label>

<link:label id="lab_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Accounts Payable and Accrued Liabilities </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:to="lab_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DebtWeightedAverageInterestRate_d3660e0d-baa7-4c86-90ad-f38574587bd7_terseLabel_en-US" xlink:label="lab_us-gaap_DebtWeightedAverageInterestRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted average interest rate on debt outstanding </link:label>

<link:label id="lab_us-gaap_DebtWeightedAverageInterestRate_af0f0883-ead5-4ddc-915c-abbc65488c76_verboseLabel_en-US" xlink:label="lab_us-gaap_DebtWeightedAverageInterestRate" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Interest Rate on Fixed Rate Debt </link:label>

<link:label id="lab_us-gaap_DebtWeightedAverageInterestRate_label_en-US" xlink:label="lab_us-gaap_DebtWeightedAverageInterestRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt, Weighted Average Interest Rate </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtWeightedAverageInterestRate" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtWeightedAverageInterestRate"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtWeightedAverageInterestRate" xlink:to="lab_us-gaap_DebtWeightedAverageInterestRate" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DueToRelatedPartiesCurrentAndNoncurrent_969cd371-33e9-4052-9c63-3dc21cb9f8e8_verboseLabel_en-US" xlink:label="lab_us-gaap_DueToRelatedPartiesCurrentAndNoncurrent" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Due to Adviser and Administrator </link:label>

<link:label id="lab_us-gaap_DueToRelatedPartiesCurrentAndNoncurrent_9eb05eac-d5b8-4077-b0a1-004c0f7097ea_terseLabel_en-US" xlink:label="lab_us-gaap_DueToRelatedPartiesCurrentAndNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Due to adviser and administrator </link:label>

<link:label id="lab_us-gaap_DueToRelatedPartiesCurrentAndNoncurrent_label_en-US" xlink:label="lab_us-gaap_DueToRelatedPartiesCurrentAndNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Due to Related Parties </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DueToRelatedPartiesCurrentAndNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DueToRelatedPartiesCurrentAndNoncurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DueToRelatedPartiesCurrentAndNoncurrent" xlink:to="lab_us-gaap_DueToRelatedPartiesCurrentAndNoncurrent" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SecuredLongTermDebt_b5179694-3408-4f7a-9fce-62e719193039_terseLabel_en-US" xlink:label="lab_us-gaap_SecuredLongTermDebt" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Mortgage notes payable, net </link:label>

<link:label id="lab_us-gaap_SecuredLongTermDebt_label_en-US" xlink:label="lab_us-gaap_SecuredLongTermDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Secured Long-Term Debt, Noncurrent </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredLongTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SecuredLongTermDebt"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SecuredLongTermDebt" xlink:to="lab_us-gaap_SecuredLongTermDebt" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CreditFacilityDomain_63cb633a-e5c0-4383-be6e-ed7099289779_terseLabel_en-US" xlink:label="lab_us-gaap_CreditFacilityDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Credit Facility [Domain] </link:label>

<link:label id="lab_us-gaap_CreditFacilityDomain_label_en-US" xlink:label="lab_us-gaap_CreditFacilityDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Credit Facility [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CreditFacilityDomain" xlink:to="lab_us-gaap_CreditFacilityDomain" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_EarningsPerShareBasic_624b0201-9967-401c-a5db-7f5b7110121b_verboseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareBasic" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> (Loss) Income (attributable) available to common shareholders, Basic (in dollars per share) </link:label>

<link:label id="lab_us-gaap_EarningsPerShareBasic_e22fd592-15a8-497d-b88e-d1e3afa53284_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareBasic" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Basic (loss) earnings per share of common stock (in dollars per share) </link:label>

<link:label id="lab_us-gaap_EarningsPerShareBasic_label_en-US" xlink:label="lab_us-gaap_EarningsPerShareBasic" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings Per Share, Basic </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerShareBasic"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerShareBasic" xlink:to="lab_us-gaap_EarningsPerShareBasic" xlink:type="arc" order="1"/>

<link:label id="lab_good_AshburnVirginiaOfficeBuildingMember_e0983508-6778-456e-999d-25a454f1c86c_terseLabel_en-US" xlink:label="lab_good_AshburnVirginiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ashburn, Virginia Office Building </link:label>

<link:label id="lab_good_AshburnVirginiaOfficeBuildingMember_label_en-US" xlink:label="lab_good_AshburnVirginiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ashburn Virginia Office Building [Member] </link:label>

<link:label id="lab_good_AshburnVirginiaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_AshburnVirginiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ashburn Virginia office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AshburnVirginiaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_AshburnVirginiaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AshburnVirginiaOfficeBuildingMember" xlink:to="lab_good_AshburnVirginiaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_PacificMissouriMember_b3c59cd9-d711-4f72-8c08-2f09368b179a_terseLabel_en-US" xlink:label="lab_good_PacificMissouriMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pacific, Missouri </link:label>

<link:label id="lab_good_PacificMissouriMember_label_en-US" xlink:label="lab_good_PacificMissouriMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pacific, Missouri [Member] </link:label>

<link:label id="lab_good_PacificMissouriMember_documentation_en-US" xlink:label="lab_good_PacificMissouriMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pacific, Missouri </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PacificMissouriMember" xlink:href="good-20221231.xsd#good_PacificMissouriMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PacificMissouriMember" xlink:to="lab_good_PacificMissouriMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_HapevilleGeorgiaOfficeBuildingMember_e39d07e6-93e8-4244-ace7-99f609d474d3_terseLabel_en-US" xlink:label="lab_good_HapevilleGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hapeville, Georgia Office Building </link:label>

<link:label id="lab_good_HapevilleGeorgiaOfficeBuildingMember_label_en-US" xlink:label="lab_good_HapevilleGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hapeville Georgia Office Building [Member] </link:label>

<link:label id="lab_good_HapevilleGeorgiaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_HapevilleGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hapeville, Georgia Office Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_HapevilleGeorgiaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_HapevilleGeorgiaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_HapevilleGeorgiaOfficeBuildingMember" xlink:to="lab_good_HapevilleGeorgiaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_BridgetonNewJerseyIndustrialBuildingMember_01ed2889-fc5c-47c4-8f9f-efea5f4d37f3_terseLabel_en-US" xlink:label="lab_good_BridgetonNewJerseyIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Bridgeton, New Jersey Industrial Building </link:label>

<link:label id="lab_good_BridgetonNewJerseyIndustrialBuildingMember_label_en-US" xlink:label="lab_good_BridgetonNewJerseyIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Bridgeton, New Jersey Industrial Building [Member] </link:label>

<link:label id="lab_good_BridgetonNewJerseyIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_BridgetonNewJerseyIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Bridgeton, New Jersey Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BridgetonNewJerseyIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_BridgetonNewJerseyIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BridgetonNewJerseyIndustrialBuildingMember" xlink:to="lab_good_BridgetonNewJerseyIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_srt_OwnershipDomain_71c2d572-da06-45cd-aa0e-cfb0a90ae2f9_terseLabel_en-US" xlink:label="lab_srt_OwnershipDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ownership [Domain] </link:label>

<link:label id="lab_srt_OwnershipDomain_label_en-US" xlink:label="lab_srt_OwnershipDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ownership [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_OwnershipDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_OwnershipDomain" xlink:to="lab_srt_OwnershipDomain" xlink:type="arc" order="1"/>

<link:label id="lab_good_PaymentsToAcquireRealEstateAndIntangibleAssets_df77c43a-da45-47b7-b27c-60e74e2fc050_negatedLabel_en-US" xlink:label="lab_good_PaymentsToAcquireRealEstateAndIntangibleAssets" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Acquisition of real estate and related intangible assets </link:label>

<link:label id="lab_good_PaymentsToAcquireRealEstateAndIntangibleAssets_label_en-US" xlink:label="lab_good_PaymentsToAcquireRealEstateAndIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments To Acquire Real Estate And Intangible Assets </link:label>

<link:label id="lab_good_PaymentsToAcquireRealEstateAndIntangibleAssets_documentation_en-US" xlink:label="lab_good_PaymentsToAcquireRealEstateAndIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments to acquire real estate and intangible assets. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PaymentsToAcquireRealEstateAndIntangibleAssets" xlink:href="good-20221231.xsd#good_PaymentsToAcquireRealEstateAndIntangibleAssets"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PaymentsToAcquireRealEstateAndIntangibleAssets" xlink:to="lab_good_PaymentsToAcquireRealEstateAndIntangibleAssets" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DerivativeInstrumentsGainLossLineItems_626f0b69-df14-4d32-ae7f-35f2dba30161_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeInstrumentsGainLossLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Instruments, Gain (Loss) [Line Items] </link:label>

<link:label id="lab_us-gaap_DerivativeInstrumentsGainLossLineItems_label_en-US" xlink:label="lab_us-gaap_DerivativeInstrumentsGainLossLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Instruments, Gain (Loss) [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems" xlink:to="lab_us-gaap_DerivativeInstrumentsGainLossLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityInteractiveDataCurrent_0fe17396-ef99-4fec-bda3-318b4c132845_terseLabel_en-US" xlink:label="lab_dei_EntityInteractiveDataCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Interactive Data Current </link:label>

<link:label id="lab_dei_EntityInteractiveDataCurrent_label_en-US" xlink:label="lab_dei_EntityInteractiveDataCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Interactive Data Current </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityInteractiveDataCurrent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityInteractiveDataCurrent" xlink:to="lab_dei_EntityInteractiveDataCurrent" xlink:type="arc" order="1"/>

<link:label id="lab_good_VariableRateTermLoanFacilityAMember_235fbf39-cf84-4951-8ef9-cbf767665792_terseLabel_en-US" xlink:label="lab_good_VariableRateTermLoanFacilityAMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate Term Loan Facility A </link:label>

<link:label id="lab_good_VariableRateTermLoanFacilityAMember_label_en-US" xlink:label="lab_good_VariableRateTermLoanFacilityAMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate Term Loan Facility A [Member] </link:label>

<link:label id="lab_good_VariableRateTermLoanFacilityAMember_documentation_en-US" xlink:label="lab_good_VariableRateTermLoanFacilityAMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate Term Loan Facility A </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_VariableRateTermLoanFacilityAMember" xlink:href="good-20221231.xsd#good_VariableRateTermLoanFacilityAMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_VariableRateTermLoanFacilityAMember" xlink:to="lab_good_VariableRateTermLoanFacilityAMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths_c921543f-9498-4e15-be7f-95887ab34ff5_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2023 </link:label>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessor, Operating Lease, Payment to be Received, Year One </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PaymentsForRepurchaseOfRedeemablePreferredStock_789fb619-ba03-4aad-9a4c-e7ec90af0eb4_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsForRepurchaseOfRedeemablePreferredStock" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Redemption of preferred stock </link:label>

<link:label id="lab_us-gaap_PaymentsForRepurchaseOfRedeemablePreferredStock_label_en-US" xlink:label="lab_us-gaap_PaymentsForRepurchaseOfRedeemablePreferredStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments for Repurchase of Redeemable Preferred Stock </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfRedeemablePreferredStock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsForRepurchaseOfRedeemablePreferredStock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsForRepurchaseOfRedeemablePreferredStock" xlink:to="lab_us-gaap_PaymentsForRepurchaseOfRedeemablePreferredStock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_b4be78f2-5dc1-41af-85dd-ad3070779a5c_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating changes in assets and liabilities </link:label>

<link:label id="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Operating Capital [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_LawrencevilleGeorgiaOfficeBuildingMember_52227e2a-553c-49ae-a278-760481189674_terseLabel_en-US" xlink:label="lab_good_LawrencevilleGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lawrenceville, Georgia Medical Office Building </link:label>

<link:label id="lab_good_LawrencevilleGeorgiaOfficeBuildingMember_label_en-US" xlink:label="lab_good_LawrencevilleGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lawrenceville Georgia Office Building [Member] </link:label>

<link:label id="lab_good_LawrencevilleGeorgiaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_LawrencevilleGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lawrenceville Georgia office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_LawrencevilleGeorgiaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_LawrencevilleGeorgiaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_LawrencevilleGeorgiaOfficeBuildingMember" xlink:to="lab_good_LawrencevilleGeorgiaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_JacksonvilleFloridaMember_458e600f-40da-4b68-847c-410e24489eb4_terseLabel_en-US" xlink:label="lab_good_JacksonvilleFloridaMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Jacksonville, Florida </link:label>

<link:label id="lab_good_JacksonvilleFloridaMember_label_en-US" xlink:label="lab_good_JacksonvilleFloridaMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Jacksonville, Florida [Member] </link:label>

<link:label id="lab_good_JacksonvilleFloridaMember_documentation_en-US" xlink:label="lab_good_JacksonvilleFloridaMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Jacksonville, Florida </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_JacksonvilleFloridaMember" xlink:href="good-20221231.xsd#good_JacksonvilleFloridaMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_JacksonvilleFloridaMember" xlink:to="lab_good_JacksonvilleFloridaMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StatementClassOfStockAxis_8ade44d7-3efb-42fd-beb1-5f7dc5144615_terseLabel_en-US" xlink:label="lab_us-gaap_StatementClassOfStockAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Class of Stock [Axis] </link:label>

<link:label id="lab_us-gaap_StatementClassOfStockAxis_label_en-US" xlink:label="lab_us-gaap_StatementClassOfStockAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Class of Stock [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementClassOfStockAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementClassOfStockAxis" xlink:to="lab_us-gaap_StatementClassOfStockAxis" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_60698c01-7dc9-434e-9bea-a044b7753922_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Thereafter </link:label>

<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Maturity, after Year Five </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_IncomeTaxPolicyTextBlock_2067664e-a0dc-4d57-b7ab-535bef8edea3_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Taxes </link:label>

<link:label id="lab_us-gaap_IncomeTaxPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_IncomeTaxPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Tax, Policy [Policy Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxPolicyTextBlock" xlink:to="lab_us-gaap_IncomeTaxPolicyTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_TemporaryEquitySharesIssued_1bb974e7-323a-4ee4-b0dc-a594276de112_terseLabel_en-US" xlink:label="lab_us-gaap_TemporaryEquitySharesIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Redeemable preferred stock, shares issued (in shares) </link:label>

<link:label id="lab_us-gaap_TemporaryEquitySharesIssued_label_en-US" xlink:label="lab_us-gaap_TemporaryEquitySharesIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Temporary Equity, Shares Issued </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TemporaryEquitySharesIssued"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TemporaryEquitySharesIssued" xlink:to="lab_us-gaap_TemporaryEquitySharesIssued" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_TemporaryEquityParOrStatedValuePerShare_31ad7715-aa73-4713-a4f2-bc164f84756c_verboseLabel_en-US" xlink:label="lab_us-gaap_TemporaryEquityParOrStatedValuePerShare" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Redeemable preferred stock, par value (in dollars per share) </link:label>

<link:label id="lab_us-gaap_TemporaryEquityParOrStatedValuePerShare_label_en-US" xlink:label="lab_us-gaap_TemporaryEquityParOrStatedValuePerShare" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Temporary Equity, Par or Stated Value Per Share </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityParOrStatedValuePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TemporaryEquityParOrStatedValuePerShare"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TemporaryEquityParOrStatedValuePerShare" xlink:to="lab_us-gaap_TemporaryEquityParOrStatedValuePerShare" xlink:type="arc" order="1"/>

<link:label id="lab_good_CharlotteNorthCarolinaIndustrialBuildingTwoMember_30b28f50-a947-48d4-9866-dcf1c3744838_terseLabel_en-US" xlink:label="lab_good_CharlotteNorthCarolinaIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Charlotte, North Carolina Industrial Building Two </link:label>

<link:label id="lab_good_CharlotteNorthCarolinaIndustrialBuildingTwoMember_label_en-US" xlink:label="lab_good_CharlotteNorthCarolinaIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Charlotte, North Carolina Industrial Building Two [Member] </link:label>

<link:label id="lab_good_CharlotteNorthCarolinaIndustrialBuildingTwoMember_documentation_en-US" xlink:label="lab_good_CharlotteNorthCarolinaIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Charlotte, North Carolina Industrial Building Two </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CharlotteNorthCarolinaIndustrialBuildingTwoMember" xlink:href="good-20221231.xsd#good_CharlotteNorthCarolinaIndustrialBuildingTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CharlotteNorthCarolinaIndustrialBuildingTwoMember" xlink:to="lab_good_CharlotteNorthCarolinaIndustrialBuildingTwoMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_MinimumPercentageLikelihoodToRecognizeTaxBenefitFromUncertainTaxPosition_2dac083b-007b-450a-9bf0-2a230356b930_terseLabel_en-US" xlink:label="lab_good_MinimumPercentageLikelihoodToRecognizeTaxBenefitFromUncertainTaxPosition" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Uncertain tax positions percentage </link:label>

<link:label id="lab_good_MinimumPercentageLikelihoodToRecognizeTaxBenefitFromUncertainTaxPosition_label_en-US" xlink:label="lab_good_MinimumPercentageLikelihoodToRecognizeTaxBenefitFromUncertainTaxPosition" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Minimum Percentage Likelihood To Recognize Tax Benefit From Uncertain Tax Position </link:label>

<link:label id="lab_good_MinimumPercentageLikelihoodToRecognizeTaxBenefitFromUncertainTaxPosition_documentation_en-US" xlink:label="lab_good_MinimumPercentageLikelihoodToRecognizeTaxBenefitFromUncertainTaxPosition" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Minimum percentage likelihood to recognize tax benefit from uncertain tax position. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_MinimumPercentageLikelihoodToRecognizeTaxBenefitFromUncertainTaxPosition" xlink:href="good-20221231.xsd#good_MinimumPercentageLikelihoodToRecognizeTaxBenefitFromUncertainTaxPosition"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_MinimumPercentageLikelihoodToRecognizeTaxBenefitFromUncertainTaxPosition" xlink:to="lab_good_MinimumPercentageLikelihoodToRecognizeTaxBenefitFromUncertainTaxPosition" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_56c8ae93-18ca-4b75-9e7d-c052ae68bd0e_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Finite-Lived Intangible Assets [Table] </link:label>

<link:label id="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Finite-Lived Intangible Assets [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:to="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:type="arc" order="1"/>

<link:label id="lab_good_HoustonTexasIndustrialBuildingMember_22c8acc3-f2bf-4069-b3c5-39eee9aa7ba8_terseLabel_en-US" xlink:label="lab_good_HoustonTexasIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Houston, Texas Industrial Building </link:label>

<link:label id="lab_good_HoustonTexasIndustrialBuildingMember_label_en-US" xlink:label="lab_good_HoustonTexasIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Houston, Texas Industrial Building [Member] </link:label>

<link:label id="lab_good_HoustonTexasIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_HoustonTexasIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Houston, Texas Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_HoustonTexasIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_HoustonTexasIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_HoustonTexasIndustrialBuildingMember" xlink:to="lab_good_HoustonTexasIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RelatedPartyTransactionsDisclosureTextBlock_4f565358-1a10-4ea7-8bf7-c617083de0de_terseLabel_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Related-Party Transactions </link:label>

<link:label id="lab_us-gaap_RelatedPartyTransactionsDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Related Party Transactions Disclosure [Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionsDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:to="lab_us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PreferredStockRedemptionDiscount_1c80d093-36dc-4617-872e-5e1705f2791d_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockRedemptionDiscount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gain on repurchase of Series G preferred stock </link:label>

<link:label id="lab_us-gaap_PreferredStockRedemptionDiscount_label_en-US" xlink:label="lab_us-gaap_PreferredStockRedemptionDiscount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred Stock Redemption Discount </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockRedemptionDiscount" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockRedemptionDiscount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockRedemptionDiscount" xlink:to="lab_us-gaap_PreferredStockRedemptionDiscount" xlink:type="arc" order="1"/>

<link:label id="lab_good_IncentiveFeeOnCapitalGains_8177e1d0-69bb-4f1a-9a74-bddda5060761_terseLabel_en-US" xlink:label="lab_good_IncentiveFeeOnCapitalGains" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Capital gain fee </link:label>

<link:label id="lab_good_IncentiveFeeOnCapitalGains_label_en-US" xlink:label="lab_good_IncentiveFeeOnCapitalGains" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Incentive Fee On Capital Gains </link:label>

<link:label id="lab_good_IncentiveFeeOnCapitalGains_documentation_en-US" xlink:label="lab_good_IncentiveFeeOnCapitalGains" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Incentive fee on capital gains. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_IncentiveFeeOnCapitalGains" xlink:href="good-20221231.xsd#good_IncentiveFeeOnCapitalGains"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_IncentiveFeeOnCapitalGains" xlink:to="lab_good_IncentiveFeeOnCapitalGains" xlink:type="arc" order="1"/>

<link:label id="lab_dei_DocumentFiscalYearFocus_f071fffa-188e-40fc-b1b7-76c0d458b63b_terseLabel_en-US" xlink:label="lab_dei_DocumentFiscalYearFocus" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Fiscal Year Focus </link:label>

<link:label id="lab_dei_DocumentFiscalYearFocus_label_en-US" xlink:label="lab_dei_DocumentFiscalYearFocus" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Fiscal Year Focus </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentFiscalYearFocus"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentFiscalYearFocus" xlink:to="lab_dei_DocumentFiscalYearFocus" xlink:type="arc" order="1"/>

<link:label id="lab_good_UniversalRegistrationStatementAmountAuthorized_95a83601-2707-4407-8a4a-a22ef4ba060a_terseLabel_en-US" xlink:label="lab_good_UniversalRegistrationStatementAmountAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Universal registration statement, amount authorized </link:label>

<link:label id="lab_good_UniversalRegistrationStatementAmountAuthorized_label_en-US" xlink:label="lab_good_UniversalRegistrationStatementAmountAuthorized" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Universal Registration Statement, Amount Authorized </link:label>

<link:label id="lab_good_UniversalRegistrationStatementAmountAuthorized_documentation_en-US" xlink:label="lab_good_UniversalRegistrationStatementAmountAuthorized" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Universal Registration Statement, Amount Authorized </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_UniversalRegistrationStatementAmountAuthorized" xlink:href="good-20221231.xsd#good_UniversalRegistrationStatementAmountAuthorized"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_UniversalRegistrationStatementAmountAuthorized" xlink:to="lab_good_UniversalRegistrationStatementAmountAuthorized" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_b00f0b14-5319-446e-8593-0eafd69595c2_terseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash flows from operating activities: </link:label>

<link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Cash Provided by (Used in) Operating Activities [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_FairValueOfAssetsAcquired_7cfa69eb-3196-4f06-8bea-abb0e0b3257f_verboseLabel_en-US" xlink:label="lab_us-gaap_FairValueOfAssetsAcquired" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Assets acquired </link:label>

<link:label id="lab_us-gaap_FairValueOfAssetsAcquired_label_en-US" xlink:label="lab_us-gaap_FairValueOfAssetsAcquired" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair Value of Assets Acquired </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueOfAssetsAcquired" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueOfAssetsAcquired"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueOfAssetsAcquired" xlink:to="lab_us-gaap_FairValueOfAssetsAcquired" xlink:type="arc" order="1"/>

<link:label id="lab_good_RealEstateAndAccumulatedDepreciationThirdYearOfConstructionOrImprovements_663792f8-2eea-4a7a-9e3b-7766b644a59d_terseLabel_en-US" xlink:label="lab_good_RealEstateAndAccumulatedDepreciationThirdYearOfConstructionOrImprovements" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Year construction/improvements two </link:label>

<link:label id="lab_good_RealEstateAndAccumulatedDepreciationThirdYearOfConstructionOrImprovements_label_en-US" xlink:label="lab_good_RealEstateAndAccumulatedDepreciationThirdYearOfConstructionOrImprovements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate And Accumulated Depreciation Third Year Of Construction Or Improvements </link:label>

<link:label id="lab_good_RealEstateAndAccumulatedDepreciationThirdYearOfConstructionOrImprovements_documentation_en-US" xlink:label="lab_good_RealEstateAndAccumulatedDepreciationThirdYearOfConstructionOrImprovements" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real estate and accumulated depreciation, year of construction two. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_RealEstateAndAccumulatedDepreciationThirdYearOfConstructionOrImprovements" xlink:href="good-20221231.xsd#good_RealEstateAndAccumulatedDepreciationThirdYearOfConstructionOrImprovements"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_RealEstateAndAccumulatedDepreciationThirdYearOfConstructionOrImprovements" xlink:to="lab_good_RealEstateAndAccumulatedDepreciationThirdYearOfConstructionOrImprovements" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_GeneralPartnersCapitalAccountUnitsIssued_4fbf7171-013b-4977-8c5e-2f075e0e6dec_terseLabel_en-US" xlink:label="lab_us-gaap_GeneralPartnersCapitalAccountUnitsIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Units issued </link:label>

<link:label id="lab_us-gaap_GeneralPartnersCapitalAccountUnitsIssued_label_en-US" xlink:label="lab_us-gaap_GeneralPartnersCapitalAccountUnitsIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> General Partners' Capital Account, Units Issued </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralPartnersCapitalAccountUnitsIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GeneralPartnersCapitalAccountUnitsIssued"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GeneralPartnersCapitalAccountUnitsIssued" xlink:to="lab_us-gaap_GeneralPartnersCapitalAccountUnitsIssued" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DerivativeCapInterestRate_54131711-5268-4e2f-817e-91d74e5c39c6_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeCapInterestRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest rate </link:label>

<link:label id="lab_us-gaap_DerivativeCapInterestRate_label_en-US" xlink:label="lab_us-gaap_DerivativeCapInterestRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative, Cap Interest Rate </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeCapInterestRate" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeCapInterestRate"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeCapInterestRate" xlink:to="lab_us-gaap_DerivativeCapInterestRate" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_InvestmentBuildingAndBuildingImprovements_945e52e3-ba04-4abf-af80-7d5981d36315_terseLabel_en-US" xlink:label="lab_us-gaap_InvestmentBuildingAndBuildingImprovements" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Building and improvements </link:label>

<link:label id="lab_us-gaap_InvestmentBuildingAndBuildingImprovements_label_en-US" xlink:label="lab_us-gaap_InvestmentBuildingAndBuildingImprovements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Investment Building and Building Improvements </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentBuildingAndBuildingImprovements" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InvestmentBuildingAndBuildingImprovements"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InvestmentBuildingAndBuildingImprovements" xlink:to="lab_us-gaap_InvestmentBuildingAndBuildingImprovements" xlink:type="arc" order="1"/>

<link:label id="lab_good_DistributionsAttributableToSeniorCommonStock_b320be4c-2676-4f00-af2c-84ffaf623d86_negatedLabel_en-US" xlink:label="lab_good_DistributionsAttributableToSeniorCommonStock" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Distributions attributable to senior common stock </link:label>

<link:label id="lab_good_DistributionsAttributableToSeniorCommonStock_label_en-US" xlink:label="lab_good_DistributionsAttributableToSeniorCommonStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Distributions Attributable To Senior Common Stock </link:label>

<link:label id="lab_good_DistributionsAttributableToSeniorCommonStock_documentation_en-US" xlink:label="lab_good_DistributionsAttributableToSeniorCommonStock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Distributions attributable to senior common stock. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DistributionsAttributableToSeniorCommonStock" xlink:href="good-20221231.xsd#good_DistributionsAttributableToSeniorCommonStock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DistributionsAttributableToSeniorCommonStock" xlink:to="lab_good_DistributionsAttributableToSeniorCommonStock" xlink:type="arc" order="1"/>

<link:label id="lab_good_WilmingtonNorthCarolinaThreeIndustrialBuildingMember_03395536-b014-4e78-a803-ab77ba281733_terseLabel_en-US" xlink:label="lab_good_WilmingtonNorthCarolinaThreeIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilmington, North Carolina Three Industrial Building </link:label>

<link:label id="lab_good_WilmingtonNorthCarolinaThreeIndustrialBuildingMember_label_en-US" xlink:label="lab_good_WilmingtonNorthCarolinaThreeIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilmington, North Carolina Three Industrial Building [Member] </link:label>

<link:label id="lab_good_WilmingtonNorthCarolinaThreeIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_WilmingtonNorthCarolinaThreeIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilmington, North Carolina Three Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_WilmingtonNorthCarolinaThreeIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_WilmingtonNorthCarolinaThreeIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_WilmingtonNorthCarolinaThreeIndustrialBuildingMember" xlink:to="lab_good_WilmingtonNorthCarolinaThreeIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis_456d9c40-b15d-4636-aee4-55686186a5f6_terseLabel_en-US" xlink:label="lab_us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Legal Entity of Counterparty, Type [Axis] </link:label>

<link:label id="lab_us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis_label_en-US" xlink:label="lab_us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Legal Entity of Counterparty, Type [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis" xlink:to="lab_us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis" xlink:type="arc" order="1"/>

<link:label id="lab_good_ScheduleOfRealEstateOwnedHeldForSaleTableTableTextBlock_5554db82-a674-4194-b700-c903f8f96434_terseLabel_en-US" xlink:label="lab_good_ScheduleOfRealEstateOwnedHeldForSaleTableTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Components of Assets and Liabilities Held for Sale </link:label>

<link:label id="lab_good_ScheduleOfRealEstateOwnedHeldForSaleTableTableTextBlock_label_en-US" xlink:label="lab_good_ScheduleOfRealEstateOwnedHeldForSaleTableTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Real Estate Owned Held For Sale Table [Table Text Block] </link:label>

<link:label id="lab_good_ScheduleOfRealEstateOwnedHeldForSaleTableTableTextBlock_documentation_en-US" xlink:label="lab_good_ScheduleOfRealEstateOwnedHeldForSaleTableTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Real Estate Owned Held For Sale Table [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ScheduleOfRealEstateOwnedHeldForSaleTableTableTextBlock" xlink:href="good-20221231.xsd#good_ScheduleOfRealEstateOwnedHeldForSaleTableTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ScheduleOfRealEstateOwnedHeldForSaleTableTableTextBlock" xlink:to="lab_good_ScheduleOfRealEstateOwnedHeldForSaleTableTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_6a73f852-8124-4fd1-9dd4-6cba84bb2658_negatedLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Premiums and discounts, net </link:label>

<link:label id="lab_us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Unamortized Discount (Premium), Net </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:to="lab_us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CommonStockSharesOutstanding_94ad4792-1dc8-4742-bf9c-1f7f856825ea_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common stock, shares outstanding (in shares) </link:label>

<link:label id="lab_us-gaap_CommonStockSharesOutstanding_65c0f695-3bc4-4f71-ba1d-b07f12c85760_periodStartLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common stock, beginning balance (in shares) </link:label>

<link:label id="lab_us-gaap_CommonStockSharesOutstanding_d92c6545-e68b-4a7f-88f6-002c765dffff_periodEndLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common stock, ending balance (in shares) </link:label>

<link:label id="lab_us-gaap_CommonStockSharesOutstanding_label_en-US" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock, Shares, Outstanding </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesOutstanding"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockSharesOutstanding" xlink:to="lab_us-gaap_CommonStockSharesOutstanding" xlink:type="arc" order="1"/>

<link:label id="lab_good_RealEstateHeldForSaleMember_c75b28fc-84a9-4d46-8b7e-977e515a1d7d_verboseLabel_en-US" xlink:label="lab_good_RealEstateHeldForSaleMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Held For Sale </link:label>

<link:label id="lab_good_RealEstateHeldForSaleMember_5ed5673e-3110-463f-8655-9d59dad6e533_terseLabel_en-US" xlink:label="lab_good_RealEstateHeldForSaleMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Held for Sale </link:label>

<link:label id="lab_good_RealEstateHeldForSaleMember_label_en-US" xlink:label="lab_good_RealEstateHeldForSaleMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Held For Sale [Member] </link:label>

<link:label id="lab_good_RealEstateHeldForSaleMember_documentation_en-US" xlink:label="lab_good_RealEstateHeldForSaleMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real estate held for sale. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_RealEstateHeldForSaleMember" xlink:href="good-20221231.xsd#good_RealEstateHeldForSaleMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_RealEstateHeldForSaleMember" xlink:to="lab_good_RealEstateHeldForSaleMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PropertyPlantAndEquipmentByTypeAxis_5e55dcae-0f6b-4a7b-b610-7ac00eb69878_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment, Type [Axis] </link:label>

<link:label id="lab_us-gaap_PropertyPlantAndEquipmentByTypeAxis_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Lived Tangible Asset [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:type="arc" order="1"/>

<link:label id="lab_good_NoncashorPartNoncashAcquisitionImprovementsIncludedinAccountsPayableandAccruedLiabilities_496d117d-db95-4b32-9bf1-c28bd15e290f_terseLabel_en-US" xlink:label="lab_good_NoncashorPartNoncashAcquisitionImprovementsIncludedinAccountsPayableandAccruedLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Capital improvements and leasing commissions included in accounts payable and accrued expenses </link:label>

<link:label id="lab_good_NoncashorPartNoncashAcquisitionImprovementsIncludedinAccountsPayableandAccruedLiabilities_label_en-US" xlink:label="lab_good_NoncashorPartNoncashAcquisitionImprovementsIncludedinAccountsPayableandAccruedLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncash or Part Noncash Acquisition, Improvements Included in Accounts Payable and Accrued Liabilities </link:label>

<link:label id="lab_good_NoncashorPartNoncashAcquisitionImprovementsIncludedinAccountsPayableandAccruedLiabilities_documentation_en-US" xlink:label="lab_good_NoncashorPartNoncashAcquisitionImprovementsIncludedinAccountsPayableandAccruedLiabilities" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncash or Part Noncash Acquisition, Improvements Included in Accounts Payable and Accrued Liabilities </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NoncashorPartNoncashAcquisitionImprovementsIncludedinAccountsPayableandAccruedLiabilities" xlink:href="good-20221231.xsd#good_NoncashorPartNoncashAcquisitionImprovementsIncludedinAccountsPayableandAccruedLiabilities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NoncashorPartNoncashAcquisitionImprovementsIncludedinAccountsPayableandAccruedLiabilities" xlink:to="lab_good_NoncashorPartNoncashAcquisitionImprovementsIncludedinAccountsPayableandAccruedLiabilities" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NotesPayable_34ec8beb-80cd-4af1-9e40-8b66e09d5b52_terseLabel_en-US" xlink:label="lab_us-gaap_NotesPayable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Borrowings under Term Loan A, Term Loan B and Term Loan C, net </link:label>

<link:label id="lab_us-gaap_NotesPayable_label_en-US" xlink:label="lab_us-gaap_NotesPayable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Notes Payable </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesPayable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NotesPayable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NotesPayable" xlink:to="lab_us-gaap_NotesPayable" xlink:type="arc" order="1"/>

<link:label id="lab_good_PeruIllinoisIndustrialBuildingTwoMember_998f5de6-db73-417d-8c5d-dde5ffae3c9c_terseLabel_en-US" xlink:label="lab_good_PeruIllinoisIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Peru, Illinois Industrial Building Two </link:label>

<link:label id="lab_good_PeruIllinoisIndustrialBuildingTwoMember_label_en-US" xlink:label="lab_good_PeruIllinoisIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Peru, Illinois Industrial Building Two [Member] </link:label>

<link:label id="lab_good_PeruIllinoisIndustrialBuildingTwoMember_documentation_en-US" xlink:label="lab_good_PeruIllinoisIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Peru, Illinois Industrial Building Two </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PeruIllinoisIndustrialBuildingTwoMember" xlink:href="good-20221231.xsd#good_PeruIllinoisIndustrialBuildingTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PeruIllinoisIndustrialBuildingTwoMember" xlink:to="lab_good_PeruIllinoisIndustrialBuildingTwoMember" xlink:type="arc" order="1"/>

<link:label id="lab_srt_SegmentGeographicalDomain_7cbbed02-9614-41d0-9d1a-bca155edc525_terseLabel_en-US" xlink:label="lab_srt_SegmentGeographicalDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Geographical [Domain] </link:label>

<link:label id="lab_srt_SegmentGeographicalDomain_label_en-US" xlink:label="lab_srt_SegmentGeographicalDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Geographical [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_SegmentGeographicalDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_SegmentGeographicalDomain" xlink:to="lab_srt_SegmentGeographicalDomain" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityPublicFloat_fb0425e6-326c-4dc1-8ae5-1eec0a37e592_terseLabel_en-US" xlink:label="lab_dei_EntityPublicFloat" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Public Float </link:label>

<link:label id="lab_dei_EntityPublicFloat_label_en-US" xlink:label="lab_dei_EntityPublicFloat" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Public Float </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityPublicFloat" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityPublicFloat"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityPublicFloat" xlink:to="lab_dei_EntityPublicFloat" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AssetRetirementObligation_dc42afd2-9b3a-4eec-90a6-b57ef789e0cb_terseLabel_en-US" xlink:label="lab_us-gaap_AssetRetirementObligation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset retirement obligation </link:label>

<link:label id="lab_us-gaap_AssetRetirementObligation_label_en-US" xlink:label="lab_us-gaap_AssetRetirementObligation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset Retirement Obligation </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetRetirementObligation" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetRetirementObligation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetRetirementObligation" xlink:to="lab_us-gaap_AssetRetirementObligation" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DerivativeLiabilities_cab1003d-12ae-482d-abbc-4b2d6672c6ad_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_DerivativeLiabilities" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative liability </link:label>

<link:label id="lab_us-gaap_DerivativeLiabilities_label_en-US" xlink:label="lab_us-gaap_DerivativeLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Liability </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeLiabilities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeLiabilities" xlink:to="lab_us-gaap_DerivativeLiabilities" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LiabilitiesAssumed1_238e3b47-5993-4808-80d4-da1ba20a3ef3_negatedLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesAssumed1" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liabilities assumed </link:label>

<link:label id="lab_us-gaap_LiabilitiesAssumed1_label_en-US" xlink:label="lab_us-gaap_LiabilitiesAssumed1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liabilities Assumed </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAssumed1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LiabilitiesAssumed1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesAssumed1" xlink:to="lab_us-gaap_LiabilitiesAssumed1" xlink:type="arc" order="1"/>

<link:label id="lab_good_FortWorthTexasOfficeMember_05bd18cc-be02-48e1-aea8-84325a9723f8_terseLabel_en-US" xlink:label="lab_good_FortWorthTexasOfficeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fort Worth, Texas Industrial Building </link:label>

<link:label id="lab_good_FortWorthTexasOfficeMember_label_en-US" xlink:label="lab_good_FortWorthTexasOfficeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fort Worth Texas Office [Member] </link:label>

<link:label id="lab_good_FortWorthTexasOfficeMember_documentation_en-US" xlink:label="lab_good_FortWorthTexasOfficeMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fort Worth Texas office. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_FortWorthTexasOfficeMember" xlink:href="good-20221231.xsd#good_FortWorthTexasOfficeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_FortWorthTexasOfficeMember" xlink:to="lab_good_FortWorthTexasOfficeMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_ColumbusOhioOfficeBuildingMember_79b1cf43-fe4f-42a9-884f-e8609ef044c1_terseLabel_en-US" xlink:label="lab_good_ColumbusOhioOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbus, Ohio (3) Office Building </link:label>

<link:label id="lab_good_ColumbusOhioOfficeBuildingMember_label_en-US" xlink:label="lab_good_ColumbusOhioOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbus, Ohio Office Building [Member] </link:label>

<link:label id="lab_good_ColumbusOhioOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_ColumbusOhioOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbus, Ohio Office Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ColumbusOhioOfficeBuildingMember" xlink:href="good-20221231.xsd#good_ColumbusOhioOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ColumbusOhioOfficeBuildingMember" xlink:to="lab_good_ColumbusOhioOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_RelatedPartyTransactionNumberOfTimesTheSumOfTheAverageAnnualBaseManagementFeeAndIncentiveFeeEarnedByAdviser_50c45bce-c51d-4a75-8a19-92f2b8363191_terseLabel_en-US" xlink:label="lab_good_RelatedPartyTransactionNumberOfTimesTheSumOfTheAverageAnnualBaseManagementFeeAndIncentiveFeeEarnedByAdviser" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of times the sum of the average annual base management fee and incentive fee earned by adviser </link:label>

<link:label id="lab_good_RelatedPartyTransactionNumberOfTimesTheSumOfTheAverageAnnualBaseManagementFeeAndIncentiveFeeEarnedByAdviser_label_en-US" xlink:label="lab_good_RelatedPartyTransactionNumberOfTimesTheSumOfTheAverageAnnualBaseManagementFeeAndIncentiveFeeEarnedByAdviser" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Related Party Transaction, Number of Times the Sum of the Average Annual Base Management Fee and Incentive Fee Earned By Adviser </link:label>

<link:label id="lab_good_RelatedPartyTransactionNumberOfTimesTheSumOfTheAverageAnnualBaseManagementFeeAndIncentiveFeeEarnedByAdviser_documentation_en-US" xlink:label="lab_good_RelatedPartyTransactionNumberOfTimesTheSumOfTheAverageAnnualBaseManagementFeeAndIncentiveFeeEarnedByAdviser" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Related Party Transaction, Number of Times the Sum of the Average Annual Base Management Fee and Incentive Fee Earned By Adviser </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_RelatedPartyTransactionNumberOfTimesTheSumOfTheAverageAnnualBaseManagementFeeAndIncentiveFeeEarnedByAdviser" xlink:href="good-20221231.xsd#good_RelatedPartyTransactionNumberOfTimesTheSumOfTheAverageAnnualBaseManagementFeeAndIncentiveFeeEarnedByAdviser"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_RelatedPartyTransactionNumberOfTimesTheSumOfTheAverageAnnualBaseManagementFeeAndIncentiveFeeEarnedByAdviser" xlink:to="lab_good_RelatedPartyTransactionNumberOfTimesTheSumOfTheAverageAnnualBaseManagementFeeAndIncentiveFeeEarnedByAdviser" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CommonStockValue_b40041c3-16d9-47f6-9e46-8b3fd15b34f8_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common stock, par value $0.001 per share, 62,292,200 and 62,290,000 shares authorized and 39,607,009 and 37,473,587 shares issued and outstanding at December 31, 2022 and December 31, 2021, respectively </link:label>

<link:label id="lab_us-gaap_CommonStockValue_label_en-US" xlink:label="lab_us-gaap_CommonStockValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock, Value, Issued </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockValue" xlink:to="lab_us-gaap_CommonStockValue" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DebtInstrumentNameDomain_b1539672-ebee-4eda-bd5b-b9a8dfa1afd1_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Name [Domain] </link:label>

<link:label id="lab_us-gaap_DebtInstrumentNameDomain_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Name [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="lab_us-gaap_DebtInstrumentNameDomain" xlink:type="arc" order="1"/>

<link:label id="lab_good_NoticePeriodForTerminationOfAgreementWithCause_2b8a267d-d6cb-4899-a64e-95967a92bf13_terseLabel_en-US" xlink:label="lab_good_NoticePeriodForTerminationOfAgreementWithCause" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Notice period for termination of agreement with cause </link:label>

<link:label id="lab_good_NoticePeriodForTerminationOfAgreementWithCause_label_en-US" xlink:label="lab_good_NoticePeriodForTerminationOfAgreementWithCause" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Notice Period For Termination Of Agreement With Cause </link:label>

<link:label id="lab_good_NoticePeriodForTerminationOfAgreementWithCause_documentation_en-US" xlink:label="lab_good_NoticePeriodForTerminationOfAgreementWithCause" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Notice period for termination of agreement with cause. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NoticePeriodForTerminationOfAgreementWithCause" xlink:href="good-20221231.xsd#good_NoticePeriodForTerminationOfAgreementWithCause"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NoticePeriodForTerminationOfAgreementWithCause" xlink:to="lab_good_NoticePeriodForTerminationOfAgreementWithCause" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PreferredStockMember_a8e85e97-ecee-4b2d-b1c9-eac9031986f3_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred Stock </link:label>

<link:label id="lab_us-gaap_PreferredStockMember_label_en-US" xlink:label="lab_us-gaap_PreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred Stock [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockMember" xlink:to="lab_us-gaap_PreferredStockMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_IndianapolisIndianaOfficeBuildingMember_b0cc34d2-6cf9-44cb-900f-f9108b0b0429_terseLabel_en-US" xlink:label="lab_good_IndianapolisIndianaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indianapolis, Indiana Office Building </link:label>

<link:label id="lab_good_IndianapolisIndianaOfficeBuildingMember_label_en-US" xlink:label="lab_good_IndianapolisIndianaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indianapolis, Indiana Office Building [Member] </link:label>

<link:label id="lab_good_IndianapolisIndianaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_IndianapolisIndianaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indianapolis, Indiana Office Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_IndianapolisIndianaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_IndianapolisIndianaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_IndianapolisIndianaOfficeBuildingMember" xlink:to="lab_good_IndianapolisIndianaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_643ad128-477c-4299-a35e-401e3f055b61_periodStartLabel_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash, cash equivalents, and restricted cash at beginning of period </link:label>

<link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_73562bfe-7845-4184-b378-c5e6eec8e877_periodEndLabel_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash, cash equivalents, and restricted cash at end of period </link:label>

<link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_0c33e242-2529-4d9c-a4ff-c9c77819336d_totalLabel_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total cash, cash equivalents, and restricted cash shown in the consolidated statement of cash flows </link:label>

<link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_label_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:to="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:type="arc" order="1"/>

<link:label id="lab_good_BaytownTexasIndustrialBuildingMember_18f1ac4a-78ee-4221-a1f8-fa15eb474d9c_terseLabel_en-US" xlink:label="lab_good_BaytownTexasIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Baytown, Texas Industrial Building </link:label>

<link:label id="lab_good_BaytownTexasIndustrialBuildingMember_label_en-US" xlink:label="lab_good_BaytownTexasIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Baytown, Texas Industrial Building [Member] </link:label>

<link:label id="lab_good_BaytownTexasIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_BaytownTexasIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Baytown, Texas Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BaytownTexasIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_BaytownTexasIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BaytownTexasIndustrialBuildingMember" xlink:to="lab_good_BaytownTexasIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_QuarterlyBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses_f675bb18-e884-4890-8683-c0ca2e3ef6b4_terseLabel_en-US" xlink:label="lab_good_QuarterlyBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Quarterly base management fee, in percentage of stockholders' equity, adjusted to unrealized gains or losses </link:label>

<link:label id="lab_good_QuarterlyBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses_label_en-US" xlink:label="lab_good_QuarterlyBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Quarterly Base Management Fee In Percentage Of Stockholders Equity Adjusted To Unrealized Gains Or Losses </link:label>

<link:label id="lab_good_QuarterlyBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses_documentation_en-US" xlink:label="lab_good_QuarterlyBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Quarterly base management fee in percentage of stockholders equity adjusted to unrealized gains or losses. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_QuarterlyBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses" xlink:href="good-20221231.xsd#good_QuarterlyBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_QuarterlyBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses" xlink:to="lab_good_QuarterlyBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberOfPropertiesUsedToCollateralizeMortgagesWithExtendedMaturity_5caf5ab7-5dd7-4d84-8154-7410dc0f6954_terseLabel_en-US" xlink:label="lab_good_NumberOfPropertiesUsedToCollateralizeMortgagesWithExtendedMaturity" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of properties used to collateralize mortgages with extended maturity </link:label>

<link:label id="lab_good_NumberOfPropertiesUsedToCollateralizeMortgagesWithExtendedMaturity_label_en-US" xlink:label="lab_good_NumberOfPropertiesUsedToCollateralizeMortgagesWithExtendedMaturity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Properties Used To Collateralize Mortgages With Extended Maturity </link:label>

<link:label id="lab_good_NumberOfPropertiesUsedToCollateralizeMortgagesWithExtendedMaturity_documentation_en-US" xlink:label="lab_good_NumberOfPropertiesUsedToCollateralizeMortgagesWithExtendedMaturity" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Properties Used To Collateralize Mortgages With Extended Maturity </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberOfPropertiesUsedToCollateralizeMortgagesWithExtendedMaturity" xlink:href="good-20221231.xsd#good_NumberOfPropertiesUsedToCollateralizeMortgagesWithExtendedMaturity"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberOfPropertiesUsedToCollateralizeMortgagesWithExtendedMaturity" xlink:to="lab_good_NumberOfPropertiesUsedToCollateralizeMortgagesWithExtendedMaturity" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberOfExistingEncumberedProperties_f5869ff5-9130-41ad-ae43-0af7a7088bd4_verboseLabel_en-US" xlink:label="lab_good_NumberOfExistingEncumberedProperties" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of properties collateralized in mortgage notes payable </link:label>

<link:label id="lab_good_NumberOfExistingEncumberedProperties_0c98062a-fc48-461d-9970-e57e4d9cb59b_terseLabel_en-US" xlink:label="lab_good_NumberOfExistingEncumberedProperties" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Encumbered properties </link:label>

<link:label id="lab_good_NumberOfExistingEncumberedProperties_label_en-US" xlink:label="lab_good_NumberOfExistingEncumberedProperties" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Existing Encumbered Properties </link:label>

<link:label id="lab_good_NumberOfExistingEncumberedProperties_documentation_en-US" xlink:label="lab_good_NumberOfExistingEncumberedProperties" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of existing encumbered properties. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberOfExistingEncumberedProperties" xlink:href="good-20221231.xsd#good_NumberOfExistingEncumberedProperties"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberOfExistingEncumberedProperties" xlink:to="lab_good_NumberOfExistingEncumberedProperties" xlink:type="arc" order="1"/>

<link:label id="lab_good_CoppellTexasRetailBuildingMember_da08dbbe-c3a2-42b3-a57c-070a2cbd639b_terseLabel_en-US" xlink:label="lab_good_CoppellTexasRetailBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Coppell, Texas Retail Building </link:label>

<link:label id="lab_good_CoppellTexasRetailBuildingMember_label_en-US" xlink:label="lab_good_CoppellTexasRetailBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Coppell, Texas Retail Building [Member] </link:label>

<link:label id="lab_good_CoppellTexasRetailBuildingMember_documentation_en-US" xlink:label="lab_good_CoppellTexasRetailBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Coppell, Texas Retail Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CoppellTexasRetailBuildingMember" xlink:href="good-20221231.xsd#good_CoppellTexasRetailBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CoppellTexasRetailBuildingMember" xlink:to="lab_good_CoppellTexasRetailBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_SeriesofPropertyAcquisitionsMember_b7932979-2865-4617-8d90-5ff57c4db8be_terseLabel_en-US" xlink:label="lab_good_SeriesofPropertyAcquisitionsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series of Property Acquisitions </link:label>

<link:label id="lab_good_SeriesofPropertyAcquisitionsMember_label_en-US" xlink:label="lab_good_SeriesofPropertyAcquisitionsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series of Property Acquisitions [Member] </link:label>

<link:label id="lab_good_SeriesofPropertyAcquisitionsMember_documentation_en-US" xlink:label="lab_good_SeriesofPropertyAcquisitionsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series of Property Acquisitions [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SeriesofPropertyAcquisitionsMember" xlink:href="good-20221231.xsd#good_SeriesofPropertyAcquisitionsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SeriesofPropertyAcquisitionsMember" xlink:to="lab_good_SeriesofPropertyAcquisitionsMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_OrganizationAndSignificantAccountingPoliciesTable_2ea253fe-4299-4ecc-8141-d49fa76858af_terseLabel_en-US" xlink:label="lab_good_OrganizationAndSignificantAccountingPoliciesTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Organization and Significant Accounting Policies [Table] </link:label>

<link:label id="lab_good_OrganizationAndSignificantAccountingPoliciesTable_label_en-US" xlink:label="lab_good_OrganizationAndSignificantAccountingPoliciesTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Organization And Significant Accounting Policies [Table] </link:label>

<link:label id="lab_good_OrganizationAndSignificantAccountingPoliciesTable_documentation_en-US" xlink:label="lab_good_OrganizationAndSignificantAccountingPoliciesTable" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Organization and significant accounting policies. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_OrganizationAndSignificantAccountingPoliciesTable" xlink:href="good-20221231.xsd#good_OrganizationAndSignificantAccountingPoliciesTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_OrganizationAndSignificantAccountingPoliciesTable" xlink:to="lab_good_OrganizationAndSignificantAccountingPoliciesTable" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ParentMember_f94eaddf-d614-4443-969f-294fba6cab6f_terseLabel_en-US" xlink:label="lab_us-gaap_ParentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total Stockholders' Equity </link:label>

<link:label id="lab_us-gaap_ParentMember_label_en-US" xlink:label="lab_us-gaap_ParentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Parent [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ParentMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ParentMember" xlink:to="lab_us-gaap_ParentMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_IndianapolisIndianaIndustrialBuildingTwoMember_cdba8004-483b-4014-8104-42a94ee17ce1_terseLabel_en-US" xlink:label="lab_good_IndianapolisIndianaIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indianapolis, Indiana Industrial Building Two </link:label>

<link:label id="lab_good_IndianapolisIndianaIndustrialBuildingTwoMember_label_en-US" xlink:label="lab_good_IndianapolisIndianaIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indianapolis, Indiana Industrial Building Two [Member] </link:label>

<link:label id="lab_good_IndianapolisIndianaIndustrialBuildingTwoMember_documentation_en-US" xlink:label="lab_good_IndianapolisIndianaIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indianapolis, Indiana Industrial Building Two </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_IndianapolisIndianaIndustrialBuildingTwoMember" xlink:href="good-20221231.xsd#good_IndianapolisIndianaIndustrialBuildingTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_IndianapolisIndianaIndustrialBuildingTwoMember" xlink:to="lab_good_IndianapolisIndianaIndustrialBuildingTwoMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_IncomeStatementLocationDomain_c156e094-10f4-43aa-81a1-07d171a40968_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeStatementLocationDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Statement Location [Domain] </link:label>

<link:label id="lab_us-gaap_IncomeStatementLocationDomain_label_en-US" xlink:label="lab_us-gaap_IncomeStatementLocationDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Statement Location [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeStatementLocationDomain" xlink:to="lab_us-gaap_IncomeStatementLocationDomain" xlink:type="arc" order="1"/>

<link:label id="lab_good_DraperUtahOfficeBuildingMember_a4e06c2a-fb1f-465a-bf20-5f5c71d2c3df_terseLabel_en-US" xlink:label="lab_good_DraperUtahOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Draper, Utah Office Building </link:label>

<link:label id="lab_good_DraperUtahOfficeBuildingMember_label_en-US" xlink:label="lab_good_DraperUtahOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Draper Utah Office Building [Member] </link:label>

<link:label id="lab_good_DraperUtahOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_DraperUtahOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Draper, Utah Office Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DraperUtahOfficeBuildingMember" xlink:href="good-20221231.xsd#good_DraperUtahOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DraperUtahOfficeBuildingMember" xlink:to="lab_good_DraperUtahOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_AmendmentFlag_9050adbc-f1c2-46c7-97f4-c66e84df7b02_terseLabel_en-US" xlink:label="lab_dei_AmendmentFlag" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amendment Flag </link:label>

<link:label id="lab_dei_AmendmentFlag_label_en-US" xlink:label="lab_dei_AmendmentFlag" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amendment Flag </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_AmendmentFlag"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_AmendmentFlag" xlink:to="lab_dei_AmendmentFlag" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OperatingLeaseCost_6e6a749e-589b-4c8b-98f9-a0c1f25e312e_verboseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseCost" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fixed lease payments </link:label>

<link:label id="lab_us-gaap_OperatingLeaseCost_d97b9665-d5f2-4f9c-b86c-c2fdec91c9bd_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseCost" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Expenses incurred for the properties listed </link:label>

<link:label id="lab_us-gaap_OperatingLeaseCost_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Lease, Cost </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseCost" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseCost"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseCost" xlink:to="lab_us-gaap_OperatingLeaseCost" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTax_69993eee-b7a3-49ca-ac64-9317c0333e08_totalLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive gain </link:label>

<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTax_06ce1e80-6fa5-4d94-8bc6-96ee858d2745_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Comprehensive income </link:label>

<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTax_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive Income (Loss), Net of Tax </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:to="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PreferredStockDividendsPerShareCashPaid_62ebc97a-a019-4056-9fff-9a48c40eae9f_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockDividendsPerShareCashPaid" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred stock, cash paid (in dollars per share) </link:label>

<link:label id="lab_us-gaap_PreferredStockDividendsPerShareCashPaid_label_en-US" xlink:label="lab_us-gaap_PreferredStockDividendsPerShareCashPaid" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred Stock, Dividends, Per Share, Cash Paid </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendsPerShareCashPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockDividendsPerShareCashPaid"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockDividendsPerShareCashPaid" xlink:to="lab_us-gaap_PreferredStockDividendsPerShareCashPaid" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SeriesFPreferredStockMember_e5b0f35b-6057-421c-8dfe-8441fba72bb5_terseLabel_en-US" xlink:label="lab_us-gaap_SeriesFPreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series F Preferred Stock </link:label>

<link:label id="lab_us-gaap_SeriesFPreferredStockMember_label_en-US" xlink:label="lab_us-gaap_SeriesFPreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series F Preferred Stock [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesFPreferredStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeriesFPreferredStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SeriesFPreferredStockMember" xlink:to="lab_us-gaap_SeriesFPreferredStockMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_BirminghamAlabamaOfficeBuildingMember_0592c048-96c1-412e-8155-3672ec873c75_terseLabel_en-US" xlink:label="lab_good_BirminghamAlabamaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Birmingham, Alabama Office Building </link:label>

<link:label id="lab_good_BirminghamAlabamaOfficeBuildingMember_label_en-US" xlink:label="lab_good_BirminghamAlabamaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Birmingham Alabama Office Building [Member] </link:label>

<link:label id="lab_good_BirminghamAlabamaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_BirminghamAlabamaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Birmingham, Alabama Office Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BirminghamAlabamaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_BirminghamAlabamaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BirminghamAlabamaOfficeBuildingMember" xlink:to="lab_good_BirminghamAlabamaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_SeriesGCumulativeRedeemablePreferredStockMember_c1d5df6b-76ea-4d07-a6eb-27da1da499ab_terseLabel_en-US" xlink:label="lab_good_SeriesGCumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series G Cumulative Redeemable Preferred Stock </link:label>

<link:label id="lab_good_SeriesGCumulativeRedeemablePreferredStockMember_label_en-US" xlink:label="lab_good_SeriesGCumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series G Cumulative Redeemable Preferred Stock [Member] </link:label>

<link:label id="lab_good_SeriesGCumulativeRedeemablePreferredStockMember_documentation_en-US" xlink:label="lab_good_SeriesGCumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series G Cumulative Redeemable Preferred Stock </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SeriesGCumulativeRedeemablePreferredStockMember" xlink:href="good-20221231.xsd#good_SeriesGCumulativeRedeemablePreferredStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SeriesGCumulativeRedeemablePreferredStockMember" xlink:to="lab_good_SeriesGCumulativeRedeemablePreferredStockMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_FridleyMinnesotaOfficeBuildingMember_b4bb9acb-78c6-4b3b-810e-2f9fa2d4dbaa_terseLabel_en-US" xlink:label="lab_good_FridleyMinnesotaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fridley, Minnesota Office Building </link:label>

<link:label id="lab_good_FridleyMinnesotaOfficeBuildingMember_label_en-US" xlink:label="lab_good_FridleyMinnesotaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fridley Minnesota Office Building [Member] </link:label>

<link:label id="lab_good_FridleyMinnesotaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_FridleyMinnesotaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fridley Minnesota office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_FridleyMinnesotaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_FridleyMinnesotaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_FridleyMinnesotaOfficeBuildingMember" xlink:to="lab_good_FridleyMinnesotaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_WilmingtonNorthCarolinaTwoIndustrialBuildingMember_8910ca3b-3e12-4f0d-8228-3b3440ce265f_terseLabel_en-US" xlink:label="lab_good_WilmingtonNorthCarolinaTwoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilmington, North Carolina Two Industrial Building </link:label>

<link:label id="lab_good_WilmingtonNorthCarolinaTwoIndustrialBuildingMember_label_en-US" xlink:label="lab_good_WilmingtonNorthCarolinaTwoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilmington, North Carolina Two Industrial Building [Member] </link:label>

<link:label id="lab_good_WilmingtonNorthCarolinaTwoIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_WilmingtonNorthCarolinaTwoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilmington, North Carolina Two Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_WilmingtonNorthCarolinaTwoIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_WilmingtonNorthCarolinaTwoIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_WilmingtonNorthCarolinaTwoIndustrialBuildingMember" xlink:to="lab_good_WilmingtonNorthCarolinaTwoIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_23db3255-5c7d-4e7c-b213-9e8f82a16efa_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Thereafter </link:label>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Asset, Expected Amortization, after Year Five </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:type="arc" order="1"/>

<link:label id="lab_good_MasonOhioRetailBuildingMember_a1e0d780-1f43-42e6-a445-b84a21064f0d_terseLabel_en-US" xlink:label="lab_good_MasonOhioRetailBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Mason, Ohio Retail Building </link:label>

<link:label id="lab_good_MasonOhioRetailBuildingMember_label_en-US" xlink:label="lab_good_MasonOhioRetailBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Mason Ohio Retail Building [Member] </link:label>

<link:label id="lab_good_MasonOhioRetailBuildingMember_documentation_en-US" xlink:label="lab_good_MasonOhioRetailBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Mason Ohio retail building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_MasonOhioRetailBuildingMember" xlink:href="good-20221231.xsd#good_MasonOhioRetailBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_MasonOhioRetailBuildingMember" xlink:to="lab_good_MasonOhioRetailBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_srt_CounterpartyNameAxis_c8e0bbfc-c66b-4be5-9ebf-51cd17e12b89_terseLabel_en-US" xlink:label="lab_srt_CounterpartyNameAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Counterparty Name [Axis] </link:label>

<link:label id="lab_srt_CounterpartyNameAxis_label_en-US" xlink:label="lab_srt_CounterpartyNameAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Counterparty Name [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_CounterpartyNameAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_CounterpartyNameAxis" xlink:to="lab_srt_CounterpartyNameAxis" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PaymentsForCommissions_32be274f-64de-447a-8e83-f1d448dbcdcd_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsForCommissions" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Leasing commissions paid </link:label>

<link:label id="lab_us-gaap_PaymentsForCommissions_label_en-US" xlink:label="lab_us-gaap_PaymentsForCommissions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments for Commissions </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForCommissions" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsForCommissions"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsForCommissions" xlink:to="lab_us-gaap_PaymentsForCommissions" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityIncorporationStateCountryCode_1c31611d-8cf2-488b-abdd-b6efc9b31491_terseLabel_en-US" xlink:label="lab_dei_EntityIncorporationStateCountryCode" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Incorporation, State or Country Code </link:label>

<link:label id="lab_dei_EntityIncorporationStateCountryCode_label_en-US" xlink:label="lab_dei_EntityIncorporationStateCountryCode" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Incorporation, State or Country Code </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityIncorporationStateCountryCode"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityIncorporationStateCountryCode" xlink:to="lab_dei_EntityIncorporationStateCountryCode" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfInterestRateDerivativesTableTextBlock_3e7da3ec-0701-4591-834f-192ab8d79562_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfInterestRateDerivativesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Summary of Interest Rate Cap Agreement </link:label>

<link:label id="lab_us-gaap_ScheduleOfInterestRateDerivativesTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfInterestRateDerivativesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Interest Rate Derivatives [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInterestRateDerivativesTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfInterestRateDerivativesTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfInterestRateDerivativesTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfInterestRateDerivativesTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand_d92be451-4e57-40fe-80fb-a726909ee752_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Land, total cost </link:label>

<link:label id="lab_us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand_label_en-US" xlink:label="lab_us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand" xlink:to="lab_us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense_0c0a3b62-d692-434e-bf6f-40cc23e3f054_terseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating expense </link:label>

<link:label id="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense_label_en-US" xlink:label="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Group, Including Discontinued Operation, Operating Expense </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense" xlink:to="lab_us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CommonStockSharesAuthorized_4c3cb11b-2f8c-491c-aa27-f9f5089beee0_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common stock, shares authorized (in shares) </link:label>

<link:label id="lab_us-gaap_CommonStockSharesAuthorized_label_en-US" xlink:label="lab_us-gaap_CommonStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock, Shares Authorized </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesAuthorized"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockSharesAuthorized" xlink:to="lab_us-gaap_CommonStockSharesAuthorized" xlink:type="arc" order="1"/>

<link:label id="lab_good_SellingCommissionsGrossProceedsPercentage_0a7adfa4-0099-4a27-aaa0-8a95dbd2ae48_terseLabel_en-US" xlink:label="lab_good_SellingCommissionsGrossProceedsPercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Selling commissions </link:label>

<link:label id="lab_good_SellingCommissionsGrossProceedsPercentage_label_en-US" xlink:label="lab_good_SellingCommissionsGrossProceedsPercentage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Selling Commissions, Gross Proceeds, Percentage </link:label>

<link:label id="lab_good_SellingCommissionsGrossProceedsPercentage_documentation_en-US" xlink:label="lab_good_SellingCommissionsGrossProceedsPercentage" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Selling Commissions, Gross Proceeds, Percentage </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SellingCommissionsGrossProceedsPercentage" xlink:href="good-20221231.xsd#good_SellingCommissionsGrossProceedsPercentage"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SellingCommissionsGrossProceedsPercentage" xlink:to="lab_good_SellingCommissionsGrossProceedsPercentage" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OperatingExpenses_35aa8ae6-73ed-440c-b992-977e47ab8ddd_totalLabel_en-US" xlink:label="lab_us-gaap_OperatingExpenses" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total operating expenses </link:label>

<link:label id="lab_us-gaap_OperatingExpenses_label_en-US" xlink:label="lab_us-gaap_OperatingExpenses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Expenses </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingExpenses"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingExpenses" xlink:to="lab_us-gaap_OperatingExpenses" xlink:type="arc" order="1"/>

<link:label id="lab_srt_MaximumMember_0af47570-a74c-431d-95ce-62292fdd07f3_terseLabel_en-US" xlink:label="lab_srt_MaximumMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Maximum </link:label>

<link:label id="lab_srt_MaximumMember_label_en-US" xlink:label="lab_srt_MaximumMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Maximum [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MaximumMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_MaximumMember" xlink:to="lab_srt_MaximumMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_DenverColoradoTwoIndustrialBuildingMember_ebd0b5e2-ca6c-4a29-8c6d-8a137b05104a_terseLabel_en-US" xlink:label="lab_good_DenverColoradoTwoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Denver, Colorado Two Industrial Building </link:label>

<link:label id="lab_good_DenverColoradoTwoIndustrialBuildingMember_label_en-US" xlink:label="lab_good_DenverColoradoTwoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Denver, Colorado Two Industrial Building [Member] </link:label>

<link:label id="lab_good_DenverColoradoTwoIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_DenverColoradoTwoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Denver, Colorado Two Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DenverColoradoTwoIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_DenverColoradoTwoIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DenverColoradoTwoIndustrialBuildingMember" xlink:to="lab_good_DenverColoradoTwoIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_NewAlbanyOhioIndustrialMember_3fa7c9d6-5a72-4dd5-9b37-e38327218392_terseLabel_en-US" xlink:label="lab_good_NewAlbanyOhioIndustrialMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Albany, Ohio Office Building </link:label>

<link:label id="lab_good_NewAlbanyOhioIndustrialMember_label_en-US" xlink:label="lab_good_NewAlbanyOhioIndustrialMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Albany Ohio Industrial [Member] </link:label>

<link:label id="lab_good_NewAlbanyOhioIndustrialMember_documentation_en-US" xlink:label="lab_good_NewAlbanyOhioIndustrialMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Albany Ohio industrial. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NewAlbanyOhioIndustrialMember" xlink:href="good-20221231.xsd#good_NewAlbanyOhioIndustrialMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NewAlbanyOhioIndustrialMember" xlink:to="lab_good_NewAlbanyOhioIndustrialMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfRealEstatePropertiesTableTextBlock_e213a900-7c93-40f3-9558-71d726481ff5_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfRealEstatePropertiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Components of Investments in Real Estate </link:label>

<link:label id="lab_us-gaap_ScheduleOfRealEstatePropertiesTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfRealEstatePropertiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Real Estate Properties [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRealEstatePropertiesTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfRealEstatePropertiesTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfRealEstatePropertiesTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfRealEstatePropertiesTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_5a0cc496-abf1-434f-b8de-fad5d7e349a7_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Business Acquisitions, by Acquisition [Table] </link:label>

<link:label id="lab_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Business Acquisitions, by Acquisition [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="lab_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:type="arc" order="1"/>

<link:label id="lab_good_MaximumRemainingCapacityToSellCommonStockUnderOpenMarketSaleAgreement_fde0ab53-d63b-4f96-a927-6407616106b0_terseLabel_en-US" xlink:label="lab_good_MaximumRemainingCapacityToSellCommonStockUnderOpenMarketSaleAgreement" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Open market dale agreement, value of remaining capacity </link:label>

<link:label id="lab_good_MaximumRemainingCapacityToSellCommonStockUnderOpenMarketSaleAgreement_label_en-US" xlink:label="lab_good_MaximumRemainingCapacityToSellCommonStockUnderOpenMarketSaleAgreement" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Maximum Remaining Capacity To Sell Common Stock Under Open Market Sale Agreement </link:label>

<link:label id="lab_good_MaximumRemainingCapacityToSellCommonStockUnderOpenMarketSaleAgreement_documentation_en-US" xlink:label="lab_good_MaximumRemainingCapacityToSellCommonStockUnderOpenMarketSaleAgreement" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Maximum Remaining Capacity To Sell Common Stock Under Open Market Sale Agreement </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_MaximumRemainingCapacityToSellCommonStockUnderOpenMarketSaleAgreement" xlink:href="good-20221231.xsd#good_MaximumRemainingCapacityToSellCommonStockUnderOpenMarketSaleAgreement"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_MaximumRemainingCapacityToSellCommonStockUnderOpenMarketSaleAgreement" xlink:to="lab_good_MaximumRemainingCapacityToSellCommonStockUnderOpenMarketSaleAgreement" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue_9016b1b5-6c7d-46dd-9a05-9479d8e88287_terseLabel_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash and cash equivalents </link:label>

<link:label id="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue_label_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash and Cash Equivalents, at Carrying Value </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DesignatedAsHedgingInstrumentMember_34d35194-777c-4eb0-a0a2-11ba0ed2441a_terseLabel_en-US" xlink:label="lab_us-gaap_DesignatedAsHedgingInstrumentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivatives Designated as Hedging Instruments </link:label>

<link:label id="lab_us-gaap_DesignatedAsHedgingInstrumentMember_label_en-US" xlink:label="lab_us-gaap_DesignatedAsHedgingInstrumentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Designated as Hedging Instrument [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DesignatedAsHedgingInstrumentMember" xlink:to="lab_us-gaap_DesignatedAsHedgingInstrumentMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DividendsPayableLineItems_24b9cc16-be35-457c-a09f-bff983c1898f_terseLabel_en-US" xlink:label="lab_us-gaap_DividendsPayableLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividends Payable [Line Items] </link:label>

<link:label id="lab_us-gaap_DividendsPayableLineItems_label_en-US" xlink:label="lab_us-gaap_DividendsPayableLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividends Payable [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DividendsPayableLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DividendsPayableLineItems" xlink:to="lab_us-gaap_DividendsPayableLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_BusinessAcquisitionLineItems_a5048274-e577-49ff-95dd-4427603f6d6a_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Acquisition [Line Items] </link:label>

<link:label id="lab_us-gaap_BusinessAcquisitionLineItems_label_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Acquisition [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="lab_us-gaap_BusinessAcquisitionLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_InterestRateCashFlowHedgeLiabilityAtFairValue_22e2e6be-b45b-4092-ac96-02bd49ddfdae_negatedLabel_en-US" xlink:label="lab_us-gaap_InterestRateCashFlowHedgeLiabilityAtFairValue" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate Fair Value Liability </link:label>

<link:label id="lab_us-gaap_InterestRateCashFlowHedgeLiabilityAtFairValue_label_en-US" xlink:label="lab_us-gaap_InterestRateCashFlowHedgeLiabilityAtFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest Rate Cash Flow Hedge Liability at Fair Value </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateCashFlowHedgeLiabilityAtFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateCashFlowHedgeLiabilityAtFairValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestRateCashFlowHedgeLiabilityAtFairValue" xlink:to="lab_us-gaap_InterestRateCashFlowHedgeLiabilityAtFairValue" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StockholdersEquityNoteDisclosureTextBlock_301802de-78ff-4204-b072-a4803939c424_terseLabel_en-US" xlink:label="lab_us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equity and Mezzanine Equity </link:label>

<link:label id="lab_us-gaap_StockholdersEquityNoteDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stockholders' Equity Note Disclosure [Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:to="lab_us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_ColumbusGeorgiaOfficeMember_2e85f821-6824-48b9-8fb0-0ce3d227f26d_terseLabel_en-US" xlink:label="lab_good_ColumbusGeorgiaOfficeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbus, Georgia Office Building </link:label>

<link:label id="lab_good_ColumbusGeorgiaOfficeMember_label_en-US" xlink:label="lab_good_ColumbusGeorgiaOfficeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbus Georgia Office [Member] </link:label>

<link:label id="lab_good_ColumbusGeorgiaOfficeMember_documentation_en-US" xlink:label="lab_good_ColumbusGeorgiaOfficeMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbus Georgia office. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ColumbusGeorgiaOfficeMember" xlink:href="good-20221231.xsd#good_ColumbusGeorgiaOfficeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ColumbusGeorgiaOfficeMember" xlink:to="lab_good_ColumbusGeorgiaOfficeMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_SnyderTownshipPennsylvaniaCommercialAndWarehouseBuildingMember_cfd89670-b5d6-4dd3-9324-3859800d8c1a_terseLabel_en-US" xlink:label="lab_good_SnyderTownshipPennsylvaniaCommercialAndWarehouseBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Crenshaw, Pennsylvania Industrial Building </link:label>

<link:label id="lab_good_SnyderTownshipPennsylvaniaCommercialAndWarehouseBuildingMember_label_en-US" xlink:label="lab_good_SnyderTownshipPennsylvaniaCommercialAndWarehouseBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Snyder Township Pennsylvania Commercial And Warehouse Building [Member] </link:label>

<link:label id="lab_good_SnyderTownshipPennsylvaniaCommercialAndWarehouseBuildingMember_documentation_en-US" xlink:label="lab_good_SnyderTownshipPennsylvaniaCommercialAndWarehouseBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Snyder Township Pennsylvania commercial and warehouse building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SnyderTownshipPennsylvaniaCommercialAndWarehouseBuildingMember" xlink:href="good-20221231.xsd#good_SnyderTownshipPennsylvaniaCommercialAndWarehouseBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SnyderTownshipPennsylvaniaCommercialAndWarehouseBuildingMember" xlink:to="lab_good_SnyderTownshipPennsylvaniaCommercialAndWarehouseBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_AlbuquerqueNewMexicoIndustrialBuildingMember_65a1e12c-3363-47b6-8235-00c56e679b6d_terseLabel_en-US" xlink:label="lab_good_AlbuquerqueNewMexicoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Albuquerque, New Mexico Industrial Building </link:label>

<link:label id="lab_good_AlbuquerqueNewMexicoIndustrialBuildingMember_label_en-US" xlink:label="lab_good_AlbuquerqueNewMexicoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Albuquerque, New Mexico Industrial Building [Member] </link:label>

<link:label id="lab_good_AlbuquerqueNewMexicoIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_AlbuquerqueNewMexicoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Albuquerque, New Mexico Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AlbuquerqueNewMexicoIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_AlbuquerqueNewMexicoIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AlbuquerqueNewMexicoIndustrialBuildingMember" xlink:to="lab_good_AlbuquerqueNewMexicoIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_DecaturGeorgiaOfficeBuildingThreeMember_5d58a43b-ca20-42ab-8817-d9dc84745077_terseLabel_en-US" xlink:label="lab_good_DecaturGeorgiaOfficeBuildingThreeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Decatur, Georgia Medical Office Building </link:label>

<link:label id="lab_good_DecaturGeorgiaOfficeBuildingThreeMember_label_en-US" xlink:label="lab_good_DecaturGeorgiaOfficeBuildingThreeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Decatur Georgia Office Building Three [Member] </link:label>

<link:label id="lab_good_DecaturGeorgiaOfficeBuildingThreeMember_documentation_en-US" xlink:label="lab_good_DecaturGeorgiaOfficeBuildingThreeMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Decatur Georgia office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DecaturGeorgiaOfficeBuildingThreeMember" xlink:href="good-20221231.xsd#good_DecaturGeorgiaOfficeBuildingThreeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DecaturGeorgiaOfficeBuildingThreeMember" xlink:to="lab_good_DecaturGeorgiaOfficeBuildingThreeMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_Security12bTitle_cb3796c5-1da1-4aee-9801-3f126e002ce4_terseLabel_en-US" xlink:label="lab_dei_Security12bTitle" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Title of 12(b) Security </link:label>

<link:label id="lab_dei_Security12bTitle_label_en-US" xlink:label="lab_dei_Security12bTitle" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Title of 12(b) Security </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_Security12bTitle"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_Security12bTitle" xlink:to="lab_dei_Security12bTitle" xlink:type="arc" order="1"/>

<link:label id="lab_good_SecuredOvernightFinancingRateMember_9c7779a2-e53e-4bad-9e82-35f8c09e3d69_terseLabel_en-US" xlink:label="lab_good_SecuredOvernightFinancingRateMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Secured Overnight Financing Rate </link:label>

<link:label id="lab_good_SecuredOvernightFinancingRateMember_label_en-US" xlink:label="lab_good_SecuredOvernightFinancingRateMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Secured Overnight Financing Rate [Member] </link:label>

<link:label id="lab_good_SecuredOvernightFinancingRateMember_documentation_en-US" xlink:label="lab_good_SecuredOvernightFinancingRateMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Secured Overnight Financing Rate </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SecuredOvernightFinancingRateMember" xlink:href="good-20221231.xsd#good_SecuredOvernightFinancingRateMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SecuredOvernightFinancingRateMember" xlink:to="lab_good_SecuredOvernightFinancingRateMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_LeaseIntangiblesMember_0fac9dd4-b9ff-4b39-a155-72f75eb7f103_terseLabel_en-US" xlink:label="lab_good_LeaseIntangiblesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease Intangibles </link:label>

<link:label id="lab_good_LeaseIntangiblesMember_label_en-US" xlink:label="lab_good_LeaseIntangiblesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease Intangibles [Member] </link:label>

<link:label id="lab_good_LeaseIntangiblesMember_documentation_en-US" xlink:label="lab_good_LeaseIntangiblesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease Intangibles [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_LeaseIntangiblesMember" xlink:href="good-20221231.xsd#good_LeaseIntangiblesMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_LeaseIntangiblesMember" xlink:to="lab_good_LeaseIntangiblesMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DeferredRentReceivablesNet_0b0b0f91-39ae-4583-a0a6-427fac3b8ba4_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredRentReceivablesNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred rent receivable, net </link:label>

<link:label id="lab_us-gaap_DeferredRentReceivablesNet_label_en-US" xlink:label="lab_us-gaap_DeferredRentReceivablesNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Rent Receivables, Net </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredRentReceivablesNet" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredRentReceivablesNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredRentReceivablesNet" xlink:to="lab_us-gaap_DeferredRentReceivablesNet" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NotesPayableFairValueDisclosure_d920a52e-6d12-43ce-b7dc-60bb4309ff1c_terseLabel_en-US" xlink:label="lab_us-gaap_NotesPayableFairValueDisclosure" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair value of mortgage notes payable outstanding </link:label>

<link:label id="lab_us-gaap_NotesPayableFairValueDisclosure_label_en-US" xlink:label="lab_us-gaap_NotesPayableFairValueDisclosure" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Notes Payable, Fair Value Disclosure </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesPayableFairValueDisclosure" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NotesPayableFairValueDisclosure"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NotesPayableFairValueDisclosure" xlink:to="lab_us-gaap_NotesPayableFairValueDisclosure" xlink:type="arc" order="1"/>

<link:label id="lab_good_SeniorCommonStockParValue_8b204586-d5ff-4e11-9e4a-10b8a543c042_terseLabel_en-US" xlink:label="lab_good_SeniorCommonStockParValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior common stock, par value (in dollars per share) </link:label>

<link:label id="lab_good_SeniorCommonStockParValue_label_en-US" xlink:label="lab_good_SeniorCommonStockParValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior Common Stock Par Value </link:label>

<link:label id="lab_good_SeniorCommonStockParValue_documentation_en-US" xlink:label="lab_good_SeniorCommonStockParValue" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior common stock, par value. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SeniorCommonStockParValue" xlink:href="good-20221231.xsd#good_SeniorCommonStockParValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SeniorCommonStockParValue" xlink:to="lab_good_SeniorCommonStockParValue" xlink:type="arc" order="1"/>

<link:label id="lab_good_FortPayneAlabamaMember_3723e5c7-fef9-456f-be3f-3175dea48c8a_terseLabel_en-US" xlink:label="lab_good_FortPayneAlabamaMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fort Payne, Alabama </link:label>

<link:label id="lab_good_FortPayneAlabamaMember_label_en-US" xlink:label="lab_good_FortPayneAlabamaMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fort Payne, Alabama [Member] </link:label>

<link:label id="lab_good_FortPayneAlabamaMember_documentation_en-US" xlink:label="lab_good_FortPayneAlabamaMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fort Payne, Alabama </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_FortPayneAlabamaMember" xlink:href="good-20221231.xsd#good_FortPayneAlabamaMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_FortPayneAlabamaMember" xlink:to="lab_good_FortPayneAlabamaMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SubsequentEventLineItems_31acf582-7fde-4c4d-8e0b-d5b43e7017aa_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsequent Event [Line Items] </link:label>

<link:label id="lab_us-gaap_SubsequentEventLineItems_label_en-US" xlink:label="lab_us-gaap_SubsequentEventLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsequent Event [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventLineItems" xlink:to="lab_us-gaap_SubsequentEventLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RepaymentsOfLinesOfCredit_a3932b3d-ffd0-4787-b9e4-57fd0bd7c2a8_negatedLabel_en-US" xlink:label="lab_us-gaap_RepaymentsOfLinesOfCredit" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Repayments on revolving credit facility </link:label>

<link:label id="lab_us-gaap_RepaymentsOfLinesOfCredit_label_en-US" xlink:label="lab_us-gaap_RepaymentsOfLinesOfCredit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Repayments of Lines of Credit </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLinesOfCredit" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RepaymentsOfLinesOfCredit"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RepaymentsOfLinesOfCredit" xlink:to="lab_us-gaap_RepaymentsOfLinesOfCredit" xlink:type="arc" order="1"/>

<link:label id="lab_good_DisposalGroupIncludingDiscontinuedOperationOtherIncomeExpense_7b02a3ef-da1e-4a9a-9e80-4d91f81fd0f8_verboseLabel_en-US" xlink:label="lab_good_DisposalGroupIncludingDiscontinuedOperationOtherIncomeExpense" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other income (expense), net </link:label>

<link:label id="lab_good_DisposalGroupIncludingDiscontinuedOperationOtherIncomeExpense_label_en-US" xlink:label="lab_good_DisposalGroupIncludingDiscontinuedOperationOtherIncomeExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Group, Including Discontinued Operation, Other Income (Expense) </link:label>

<link:label id="lab_good_DisposalGroupIncludingDiscontinuedOperationOtherIncomeExpense_documentation_en-US" xlink:label="lab_good_DisposalGroupIncludingDiscontinuedOperationOtherIncomeExpense" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Group, Including Discontinued Operation, Other Income (Expense) </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DisposalGroupIncludingDiscontinuedOperationOtherIncomeExpense" xlink:href="good-20221231.xsd#good_DisposalGroupIncludingDiscontinuedOperationOtherIncomeExpense"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DisposalGroupIncludingDiscontinuedOperationOtherIncomeExpense" xlink:to="lab_good_DisposalGroupIncludingDiscontinuedOperationOtherIncomeExpense" xlink:type="arc" order="1"/>

<link:label id="lab_good_SeniorCommonStockSharesOutstanding_e827a27b-17d8-42b9-a2aa-da7209d3593c_terseLabel_en-US" xlink:label="lab_good_SeniorCommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior common stock, shares outstanding (in shares) </link:label>

<link:label id="lab_good_SeniorCommonStockSharesOutstanding_label_en-US" xlink:label="lab_good_SeniorCommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior Common Stock Shares Outstanding </link:label>

<link:label id="lab_good_SeniorCommonStockSharesOutstanding_documentation_en-US" xlink:label="lab_good_SeniorCommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior common stock, shares outstanding. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SeniorCommonStockSharesOutstanding" xlink:href="good-20221231.xsd#good_SeniorCommonStockSharesOutstanding"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SeniorCommonStockSharesOutstanding" xlink:to="lab_good_SeniorCommonStockSharesOutstanding" xlink:type="arc" order="1"/>

<link:label id="lab_good_BaseManagementFee_21b488e3-220f-4bd3-8425-760ab71754aa_verboseLabel_en-US" xlink:label="lab_good_BaseManagementFee" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Base management fee </link:label>

<link:label id="lab_good_BaseManagementFee_label_en-US" xlink:label="lab_good_BaseManagementFee" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Base Management Fee </link:label>

<link:label id="lab_good_BaseManagementFee_documentation_en-US" xlink:label="lab_good_BaseManagementFee" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Base management fee. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BaseManagementFee" xlink:href="good-20221231.xsd#good_BaseManagementFee"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BaseManagementFee" xlink:to="lab_good_BaseManagementFee" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OtherNonoperatingIncome_998db90f-9dc8-4443-ac3a-99494cdb0b19_terseLabel_en-US" xlink:label="lab_us-gaap_OtherNonoperatingIncome" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other income </link:label>

<link:label id="lab_us-gaap_OtherNonoperatingIncome_label_en-US" xlink:label="lab_us-gaap_OtherNonoperatingIncome" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Nonoperating Income </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncome" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherNonoperatingIncome"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherNonoperatingIncome" xlink:to="lab_us-gaap_OtherNonoperatingIncome" xlink:type="arc" order="1"/>

<link:label id="lab_good_HickoryNorthCarolinaOfficeBuildingMember_ba9e5417-c7ce-43e2-b505-f6ab4cc24a03_terseLabel_en-US" xlink:label="lab_good_HickoryNorthCarolinaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hickory, North Carolina Office Building </link:label>

<link:label id="lab_good_HickoryNorthCarolinaOfficeBuildingMember_label_en-US" xlink:label="lab_good_HickoryNorthCarolinaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hickory North Carolina Office Building [Member] </link:label>

<link:label id="lab_good_HickoryNorthCarolinaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_HickoryNorthCarolinaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hickory North Carolina office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_HickoryNorthCarolinaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_HickoryNorthCarolinaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_HickoryNorthCarolinaOfficeBuildingMember" xlink:to="lab_good_HickoryNorthCarolinaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract_da114a82-371e-4adc-86a2-181df4dc9d23_terseLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> LIABILITIES, MEZZANINE EQUITY AND EQUITY </link:label>

<link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract_label_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liabilities and Equity [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_BuildingAndTenantImprovementsMember_a32bd6ee-57e0-49e3-b6ff-b6ee2ceb8631_terseLabel_en-US" xlink:label="lab_good_BuildingAndTenantImprovementsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Building and Improvements </link:label>

<link:label id="lab_good_BuildingAndTenantImprovementsMember_label_en-US" xlink:label="lab_good_BuildingAndTenantImprovementsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Building And Tenant Improvements [Member] </link:label>

<link:label id="lab_good_BuildingAndTenantImprovementsMember_documentation_en-US" xlink:label="lab_good_BuildingAndTenantImprovementsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Building and Tenant Improvements [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BuildingAndTenantImprovementsMember" xlink:href="good-20221231.xsd#good_BuildingAndTenantImprovementsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BuildingAndTenantImprovementsMember" xlink:to="lab_good_BuildingAndTenantImprovementsMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_ef7f075e-3522-4444-8baf-79c74e7f9421_terseLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted average shares of common stock outstanding </link:label>

<link:label id="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_label_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Number of Shares Outstanding, Diluted [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:to="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_FixedRateMortgageLoansMember_d1e5e779-5c0a-4769-8726-d05186b0c052_terseLabel_en-US" xlink:label="lab_good_FixedRateMortgageLoansMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fixed rate mortgage loans </link:label>

<link:label id="lab_good_FixedRateMortgageLoansMember_label_en-US" xlink:label="lab_good_FixedRateMortgageLoansMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fixed Rate Mortgage Loans [Member] </link:label>

<link:label id="lab_good_FixedRateMortgageLoansMember_documentation_en-US" xlink:label="lab_good_FixedRateMortgageLoansMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fixed rate mortgage loans. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_FixedRateMortgageLoansMember" xlink:href="good-20221231.xsd#good_FixedRateMortgageLoansMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_FixedRateMortgageLoansMember" xlink:to="lab_good_FixedRateMortgageLoansMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_A2020RegistrationStatementMember_f1a673b8-c9d0-40db-a660-8343bad80007_terseLabel_en-US" xlink:label="lab_good_A2020RegistrationStatementMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2020 Registration Statement </link:label>

<link:label id="lab_good_A2020RegistrationStatementMember_label_en-US" xlink:label="lab_good_A2020RegistrationStatementMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2020 Registration Statement [Member] </link:label>

<link:label id="lab_good_A2020RegistrationStatementMember_documentation_en-US" xlink:label="lab_good_A2020RegistrationStatementMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2020 Registration Statement </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_A2020RegistrationStatementMember" xlink:href="good-20221231.xsd#good_A2020RegistrationStatementMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_A2020RegistrationStatementMember" xlink:to="lab_good_A2020RegistrationStatementMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberOfLongTermMortgagesMaturityDateExtended_41a2e24b-48d6-440f-9ff4-be04d61207ec_terseLabel_en-US" xlink:label="lab_good_NumberOfLongTermMortgagesMaturityDateExtended" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of long term mortgages, maturity date extended </link:label>

<link:label id="lab_good_NumberOfLongTermMortgagesMaturityDateExtended_label_en-US" xlink:label="lab_good_NumberOfLongTermMortgagesMaturityDateExtended" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Long Term Mortgages, Maturity Date Extended </link:label>

<link:label id="lab_good_NumberOfLongTermMortgagesMaturityDateExtended_documentation_en-US" xlink:label="lab_good_NumberOfLongTermMortgagesMaturityDateExtended" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Long Term Mortgages, Maturity Date Extended </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberOfLongTermMortgagesMaturityDateExtended" xlink:href="good-20221231.xsd#good_NumberOfLongTermMortgagesMaturityDateExtended"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberOfLongTermMortgagesMaturityDateExtended" xlink:to="lab_good_NumberOfLongTermMortgagesMaturityDateExtended" xlink:type="arc" order="1"/>

<link:label id="lab_good_AustinTexasOfficeBuildingOneMember_539e9e8f-42b9-4732-ad16-87e30ae3fef8_terseLabel_en-US" xlink:label="lab_good_AustinTexasOfficeBuildingOneMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Austin, Texas Office Building </link:label>

<link:label id="lab_good_AustinTexasOfficeBuildingOneMember_label_en-US" xlink:label="lab_good_AustinTexasOfficeBuildingOneMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Austin Texas Office Building One [Member] </link:label>

<link:label id="lab_good_AustinTexasOfficeBuildingOneMember_documentation_en-US" xlink:label="lab_good_AustinTexasOfficeBuildingOneMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Austin Texas Office Building One. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AustinTexasOfficeBuildingOneMember" xlink:href="good-20221231.xsd#good_AustinTexasOfficeBuildingOneMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AustinTexasOfficeBuildingOneMember" xlink:to="lab_good_AustinTexasOfficeBuildingOneMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ProceedsFromIssuanceOfCommonStock_4084e1e6-2620-4570-b868-1a4dbe3beb9c_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from issuance of equity </link:label>

<link:label id="lab_us-gaap_ProceedsFromIssuanceOfCommonStock_label_en-US" xlink:label="lab_us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from Issuance of Common Stock </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:to="lab_us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_b5810057-ae6f-4b44-8b5c-506bcd2015f7_terseLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Basic (in shares) </link:label>

<link:label id="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_faa7e1ff-af27-419f-9fce-9d2a51ec8655_verboseLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Denominator for basic weighted average shares of common stock (in shares) </link:label>

<link:label id="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_label_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Number of Shares Outstanding, Basic </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:to="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_c238ca1f-2af4-44f4-b7e2-389ba0164498_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Groups, Including Discontinued Operations [Table] </link:label>

<link:label id="lab_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_label_en-US" xlink:label="lab_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Groups, Including Discontinued Operations [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:to="lab_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:type="arc" order="1"/>

<link:label id="lab_good_RefinancingMortgageMember_c67f8e3a-0d67-4a99-ab29-0dbc15ed5083_terseLabel_en-US" xlink:label="lab_good_RefinancingMortgageMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Refinancing Mortgage </link:label>

<link:label id="lab_good_RefinancingMortgageMember_label_en-US" xlink:label="lab_good_RefinancingMortgageMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Refinancing Mortgage [Member] </link:label>

<link:label id="lab_good_RefinancingMortgageMember_documentation_en-US" xlink:label="lab_good_RefinancingMortgageMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Refinancing Mortgage </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_RefinancingMortgageMember" xlink:href="good-20221231.xsd#good_RefinancingMortgageMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_RefinancingMortgageMember" xlink:to="lab_good_RefinancingMortgageMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_InPlaceLeasesMember_87a5aba9-bc52-43dc-b074-32cbd5b5eb10_terseLabel_en-US" xlink:label="lab_good_InPlaceLeasesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> In-place Leases </link:label>

<link:label id="lab_good_InPlaceLeasesMember_label_en-US" xlink:label="lab_good_InPlaceLeasesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> In Place Leases [Member] </link:label>

<link:label id="lab_good_InPlaceLeasesMember_documentation_en-US" xlink:label="lab_good_InPlaceLeasesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> In-place leases. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_InPlaceLeasesMember" xlink:href="good-20221231.xsd#good_InPlaceLeasesMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_InPlaceLeasesMember" xlink:to="lab_good_InPlaceLeasesMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_GainsOnPropertySalesPolicyTextBlock_3fea2d7e-ada4-48f3-9e6f-ee5b27438300_terseLabel_en-US" xlink:label="lab_good_GainsOnPropertySalesPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gains (Losses) on Sale of Real Estate, Net </link:label>

<link:label id="lab_good_GainsOnPropertySalesPolicyTextBlock_label_en-US" xlink:label="lab_good_GainsOnPropertySalesPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gains On Property Sales [Policy Text Block] </link:label>

<link:label id="lab_good_GainsOnPropertySalesPolicyTextBlock_documentation_en-US" xlink:label="lab_good_GainsOnPropertySalesPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gains on property sales. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_GainsOnPropertySalesPolicyTextBlock" xlink:href="good-20221231.xsd#good_GainsOnPropertySalesPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_GainsOnPropertySalesPolicyTextBlock" xlink:to="lab_good_GainsOnPropertySalesPolicyTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DerivativeNotionalAmount_6ea1db56-2d3a-44a1-a270-2347daf176b5_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeNotionalAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate Notional Amount </link:label>

<link:label id="lab_us-gaap_DerivativeNotionalAmount_label_en-US" xlink:label="lab_us-gaap_DerivativeNotionalAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative, Notional Amount </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeNotionalAmount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeNotionalAmount" xlink:to="lab_us-gaap_DerivativeNotionalAmount" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PreferredStockValue_a22e065c-d0be-4c77-aeae-6c25ed429a84_verboseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockValue" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series F redeemable preferred stock, par value $0.001 per share; $25 per share liquidation preference; 25,997,800 shares authorized; and 597,616 and 422,920 shares issued and outstanding at December 31, 2022 and December 31, 2021, respectively </link:label>

<link:label id="lab_us-gaap_PreferredStockValue_label_en-US" xlink:label="lab_us-gaap_PreferredStockValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred Stock, Value, Issued </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockValue" xlink:to="lab_us-gaap_PreferredStockValue" xlink:type="arc" order="1"/>

<link:label id="lab_good_VanceAlabamaIndustrialBuildingTwoMember_d6bdf350-42e9-48c9-9f41-9ac5fe8c558c_terseLabel_en-US" xlink:label="lab_good_VanceAlabamaIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vance, Alabama Industrial Building Two </link:label>

<link:label id="lab_good_VanceAlabamaIndustrialBuildingTwoMember_label_en-US" xlink:label="lab_good_VanceAlabamaIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vance, Alabama Industrial Building Two [Member] </link:label>

<link:label id="lab_good_VanceAlabamaIndustrialBuildingTwoMember_documentation_en-US" xlink:label="lab_good_VanceAlabamaIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vance, Alabama Industrial Building Two [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_VanceAlabamaIndustrialBuildingTwoMember" xlink:href="good-20221231.xsd#good_VanceAlabamaIndustrialBuildingTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_VanceAlabamaIndustrialBuildingTwoMember" xlink:to="lab_good_VanceAlabamaIndustrialBuildingTwoMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfDebtTableTextBlock_f4331186-2fe5-42fb-89b1-d3f34aae8018_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfDebtTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Summary of Long-Term Mortgages </link:label>

<link:label id="lab_us-gaap_ScheduleOfDebtTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfDebtTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Debt [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDebtTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfDebtTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfDebtTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfDebtTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityWellKnownSeasonedIssuer_aab13591-0a64-4d6e-86a4-85e2b90f7aa2_terseLabel_en-US" xlink:label="lab_dei_EntityWellKnownSeasonedIssuer" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Well-known Seasoned Issuer </link:label>

<link:label id="lab_dei_EntityWellKnownSeasonedIssuer_label_en-US" xlink:label="lab_dei_EntityWellKnownSeasonedIssuer" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Well-known Seasoned Issuer </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityWellKnownSeasonedIssuer" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityWellKnownSeasonedIssuer"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityWellKnownSeasonedIssuer" xlink:to="lab_dei_EntityWellKnownSeasonedIssuer" xlink:type="arc" order="1"/>

<link:label id="lab_good_PercentageOfIncentiveFeesOnCapitalGains_952ed0af-cc6e-4389-9fb9-9ae435afd7a9_terseLabel_en-US" xlink:label="lab_good_PercentageOfIncentiveFeesOnCapitalGains" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Capital gains-based incentive fee percentage </link:label>

<link:label id="lab_good_PercentageOfIncentiveFeesOnCapitalGains_label_en-US" xlink:label="lab_good_PercentageOfIncentiveFeesOnCapitalGains" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage Of Incentive Fees On Capital Gains </link:label>

<link:label id="lab_good_PercentageOfIncentiveFeesOnCapitalGains_documentation_en-US" xlink:label="lab_good_PercentageOfIncentiveFeesOnCapitalGains" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of incentive fees on capital gains. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PercentageOfIncentiveFeesOnCapitalGains" xlink:href="good-20221231.xsd#good_PercentageOfIncentiveFeesOnCapitalGains"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PercentageOfIncentiveFeesOnCapitalGains" xlink:to="lab_good_PercentageOfIncentiveFeesOnCapitalGains" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DebtInstrumentTable_73aec0ad-9a8d-465e-8167-656f781a635a_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Long-term Debt Instruments [Table] </link:label>

<link:label id="lab_us-gaap_DebtInstrumentTable_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Long-Term Debt Instruments [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentTable" xlink:to="lab_us-gaap_DebtInstrumentTable" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PreferredStockRedemptionPricePerShare_b5dbc757-6ff8-4762-a37e-d42a5a1b585c_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockRedemptionPricePerShare" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred stock, redemption price per share (in usd per share) </link:label>

<link:label id="lab_us-gaap_PreferredStockRedemptionPricePerShare_label_en-US" xlink:label="lab_us-gaap_PreferredStockRedemptionPricePerShare" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred Stock, Redemption Price Per Share </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockRedemptionPricePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockRedemptionPricePerShare"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockRedemptionPricePerShare" xlink:to="lab_us-gaap_PreferredStockRedemptionPricePerShare" xlink:type="arc" order="1"/>

<link:label id="lab_good_CommonStockDividendRatePercentage_05a8a8c7-748e-4b4b-9550-c16a6733c76a_terseLabel_en-US" xlink:label="lab_good_CommonStockDividendRatePercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common stock, dividend rate </link:label>

<link:label id="lab_good_CommonStockDividendRatePercentage_label_en-US" xlink:label="lab_good_CommonStockDividendRatePercentage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock Dividend Rate Percentage </link:label>

<link:label id="lab_good_CommonStockDividendRatePercentage_documentation_en-US" xlink:label="lab_good_CommonStockDividendRatePercentage" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common stock dividend rate percentage. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CommonStockDividendRatePercentage" xlink:href="good-20221231.xsd#good_CommonStockDividendRatePercentage"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CommonStockDividendRatePercentage" xlink:to="lab_good_CommonStockDividendRatePercentage" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears_aeb1e775-8169-4aac-98fd-eea4cce4b70d_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2024 </link:label>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessor, Operating Lease, Payment to be Received, Year Two </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NoncontrollingInterestMember_033773d1-3a82-4fcf-b61e-2a75c93bdd03_terseLabel_en-US" xlink:label="lab_us-gaap_NoncontrollingInterestMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Non-Controlling Interest </link:label>

<link:label id="lab_us-gaap_NoncontrollingInterestMember_label_en-US" xlink:label="lab_us-gaap_NoncontrollingInterestMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncontrolling Interest [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NoncontrollingInterestMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NoncontrollingInterestMember" xlink:to="lab_us-gaap_NoncontrollingInterestMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OperatingExpenseMember_13e7b023-9eb6-46c7-a028-4e6861623582_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingExpenseMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Expense </link:label>

<link:label id="lab_us-gaap_OperatingExpenseMember_label_en-US" xlink:label="lab_us-gaap_OperatingExpenseMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Expense [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenseMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingExpenseMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingExpenseMember" xlink:to="lab_us-gaap_OperatingExpenseMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DebtInstrumentTerm_f594e38a-83cd-457b-b21e-f626b20726cf_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentTerm" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt instrument term </link:label>

<link:label id="lab_us-gaap_DebtInstrumentTerm_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentTerm" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Term </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentTerm"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentTerm" xlink:to="lab_us-gaap_DebtInstrumentTerm" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RepaymentsOfLongTermLinesOfCredit_4fe7a04a-c3ec-4b48-8afc-443b4a843014_negatedLabel_en-US" xlink:label="lab_us-gaap_RepaymentsOfLongTermLinesOfCredit" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Repayments on term loan </link:label>

<link:label id="lab_us-gaap_RepaymentsOfLongTermLinesOfCredit_label_en-US" xlink:label="lab_us-gaap_RepaymentsOfLongTermLinesOfCredit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Repayments of Long-Term Lines of Credit </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLongTermLinesOfCredit" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RepaymentsOfLongTermLinesOfCredit"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RepaymentsOfLongTermLinesOfCredit" xlink:to="lab_us-gaap_RepaymentsOfLongTermLinesOfCredit" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LandMember_f56e524d-6cc4-4024-85f8-74ae464df416_terseLabel_en-US" xlink:label="lab_us-gaap_LandMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Land </link:label>

<link:label id="lab_us-gaap_LandMember_label_en-US" xlink:label="lab_us-gaap_LandMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Land [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LandMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LandMember" xlink:to="lab_us-gaap_LandMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_37409104-8b4a-4d3e-a771-db7fa63d4872_terseLabel_en-US" xlink:label="lab_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effect of convertible senior common stock (in shares) </link:label>

<link:label id="lab_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_label_en-US" xlink:label="lab_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:to="lab_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_EarningsPerShareDilutedAbstract_a46077ec-1c06-48a8-8fae-bc04c3520762_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareDilutedAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Calculation of diluted (loss) earnings per share of common stock: </link:label>

<link:label id="lab_us-gaap_EarningsPerShareDilutedAbstract_label_en-US" xlink:label="lab_us-gaap_EarningsPerShareDilutedAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings Per Share, Diluted [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDilutedAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerShareDilutedAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract" xlink:to="lab_us-gaap_EarningsPerShareDilutedAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_DeferredFinancingCostsPolicyPolicyTextBlock_23477880-ea79-44ae-8826-5449ac83254e_terseLabel_en-US" xlink:label="lab_good_DeferredFinancingCostsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Financing Costs </link:label>

<link:label id="lab_good_DeferredFinancingCostsPolicyPolicyTextBlock_label_en-US" xlink:label="lab_good_DeferredFinancingCostsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Financing Costs Policy [Policy Text Block] </link:label>

<link:label id="lab_good_DeferredFinancingCostsPolicyPolicyTextBlock_documentation_en-US" xlink:label="lab_good_DeferredFinancingCostsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred financing costs. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DeferredFinancingCostsPolicyPolicyTextBlock" xlink:href="good-20221231.xsd#good_DeferredFinancingCostsPolicyPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DeferredFinancingCostsPolicyPolicyTextBlock" xlink:to="lab_good_DeferredFinancingCostsPolicyPolicyTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_1826ac43-bc0b-4367-8928-f28d24725101_terseLabel_en-US" xlink:label="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Organization, Consolidation and Presentation of Financial Statements [Abstract] </link:label>

<link:label id="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_label_en-US" xlink:label="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Organization, Consolidation and Presentation of Financial Statements [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:to="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_SnellvilleGeorgiaOfficeBuildingMember_1cd19556-f030-478d-9c95-bc49b3c694a2_terseLabel_en-US" xlink:label="lab_good_SnellvilleGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Snellville, Georgia Medical Office Building </link:label>

<link:label id="lab_good_SnellvilleGeorgiaOfficeBuildingMember_label_en-US" xlink:label="lab_good_SnellvilleGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Snellville Georgia Office Building [Member] </link:label>

<link:label id="lab_good_SnellvilleGeorgiaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_SnellvilleGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Snellville Georgia office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SnellvilleGeorgiaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_SnellvilleGeorgiaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SnellvilleGeorgiaOfficeBuildingMember" xlink:to="lab_good_SnellvilleGeorgiaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_TulsaOklahomaManufacturingBuildingMember_47802091-37c4-4550-9e23-97ba2057604a_terseLabel_en-US" xlink:label="lab_good_TulsaOklahomaManufacturingBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tulsa, Oklahoma Industrial Building </link:label>

<link:label id="lab_good_TulsaOklahomaManufacturingBuildingMember_label_en-US" xlink:label="lab_good_TulsaOklahomaManufacturingBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tulsa Oklahoma Manufacturing Building [Member] </link:label>

<link:label id="lab_good_TulsaOklahomaManufacturingBuildingMember_documentation_en-US" xlink:label="lab_good_TulsaOklahomaManufacturingBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tulsa Oklahoma manufacturing building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_TulsaOklahomaManufacturingBuildingMember" xlink:href="good-20221231.xsd#good_TulsaOklahomaManufacturingBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_TulsaOklahomaManufacturingBuildingMember" xlink:to="lab_good_TulsaOklahomaManufacturingBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_NoviMichiganIndustrialBuildingMember_064c9fd7-bb39-4c0f-aa7f-f68d49863b5b_terseLabel_en-US" xlink:label="lab_good_NoviMichiganIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Novi, Michigan Industrial Building </link:label>

<link:label id="lab_good_NoviMichiganIndustrialBuildingMember_label_en-US" xlink:label="lab_good_NoviMichiganIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Novi Michigan Industrial Building [Member] </link:label>

<link:label id="lab_good_NoviMichiganIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_NoviMichiganIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Novi Michigan Industrial Building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NoviMichiganIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_NoviMichiganIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NoviMichiganIndustrialBuildingMember" xlink:to="lab_good_NoviMichiganIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_d758493c-540a-48f8-9967-05055f117fd1_terseLabel_en-US" xlink:label="lab_us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Impairment, long-lived asset, held-for-use, statement of income or comprehensive income </link:label>

<link:label id="lab_us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_label_en-US" xlink:label="lab_us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Impairment, Long-Lived Asset, Held-for-Use, Statement of Income or Comprehensive Income [Extensible Enumeration] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration" xlink:to="lab_us-gaap_ImpairmentLongLivedAssetHeldForUseStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration" xlink:type="arc" order="1"/>

<link:label id="lab_good_SeriesDCumulativeRedeemablePreferredStockMember_b3a9be7f-9569-4865-b111-886ec89e1f2f_verboseLabel_en-US" xlink:label="lab_good_SeriesDCumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series D Cumulative Redeemable Preferred Stock </link:label>

<link:label id="lab_good_SeriesDCumulativeRedeemablePreferredStockMember_label_en-US" xlink:label="lab_good_SeriesDCumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series D Cumulative Redeemable Preferred Stock [Member] </link:label>

<link:label id="lab_good_SeriesDCumulativeRedeemablePreferredStockMember_documentation_en-US" xlink:label="lab_good_SeriesDCumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series D Cumulative Redeemable Preferred Stock [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SeriesDCumulativeRedeemablePreferredStockMember" xlink:href="good-20221231.xsd#good_SeriesDCumulativeRedeemablePreferredStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SeriesDCumulativeRedeemablePreferredStockMember" xlink:to="lab_good_SeriesDCumulativeRedeemablePreferredStockMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_CurrentFiscalYearEndDate_efda6a67-2e43-4771-9abc-d57c4d6a6cc9_terseLabel_en-US" xlink:label="lab_dei_CurrentFiscalYearEndDate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Current Fiscal Year End Date </link:label>

<link:label id="lab_dei_CurrentFiscalYearEndDate_label_en-US" xlink:label="lab_dei_CurrentFiscalYearEndDate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Current Fiscal Year End Date </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_CurrentFiscalYearEndDate"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_CurrentFiscalYearEndDate" xlink:to="lab_dei_CurrentFiscalYearEndDate" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsLineItems_9971b69d-003e-488d-b9be-fa450f6582ac_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets [Line Items] </link:label>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsLineItems_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_47ff1d54-140e-4901-81a5-cce1ea421122_terseLabel_en-US" xlink:label="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real estate and related assets held for sale </link:label>

<link:label id="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_e802500e-8ac1-4a88-8615-d1e5d2d0dc5e_totalLabel_en-US" xlink:label="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total Assets Held for Sale </link:label>

<link:label id="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_label_en-US" xlink:label="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Group, Including Discontinued Operation, Assets </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:to="lab_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:type="arc" order="1"/>

<link:label id="lab_good_SpringfieldMissouriOfficeBuildingMember_f20413b0-2453-455c-8eb5-e17750581734_terseLabel_en-US" xlink:label="lab_good_SpringfieldMissouriOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Springfield, Missouri Office Building </link:label>

<link:label id="lab_good_SpringfieldMissouriOfficeBuildingMember_label_en-US" xlink:label="lab_good_SpringfieldMissouriOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Springfield Missouri Office Building [Member] </link:label>

<link:label id="lab_good_SpringfieldMissouriOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_SpringfieldMissouriOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Springfield Missouri office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SpringfieldMissouriOfficeBuildingMember" xlink:href="good-20221231.xsd#good_SpringfieldMissouriOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SpringfieldMissouriOfficeBuildingMember" xlink:to="lab_good_SpringfieldMissouriOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AssetRetirementObligationAccretionExpense_e35e6027-85dc-473f-945a-7e75f25e4647_terseLabel_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationAccretionExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Expenses recorded to general and administrative expense </link:label>

<link:label id="lab_us-gaap_AssetRetirementObligationAccretionExpense_label_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationAccretionExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset Retirement Obligation, Accretion Expense </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetRetirementObligationAccretionExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetRetirementObligationAccretionExpense"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetRetirementObligationAccretionExpense" xlink:to="lab_us-gaap_AssetRetirementObligationAccretionExpense" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_BelowMarketLeaseAccumulatedAmortization_339be26c-c04a-4e4e-8589-f85e12542579_terseLabel_en-US" xlink:label="lab_us-gaap_BelowMarketLeaseAccumulatedAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Below market leases, accumulated amortization </link:label>

<link:label id="lab_us-gaap_BelowMarketLeaseAccumulatedAmortization_label_en-US" xlink:label="lab_us-gaap_BelowMarketLeaseAccumulatedAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Below Market Lease, Accumulated Amortization </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BelowMarketLeaseAccumulatedAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BelowMarketLeaseAccumulatedAmortization"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BelowMarketLeaseAccumulatedAmortization" xlink:to="lab_us-gaap_BelowMarketLeaseAccumulatedAmortization" xlink:type="arc" order="1"/>

<link:label id="lab_good_TaylorsvilleUtahOfficeBuildingMember_6ada49db-f5a8-4ef2-b69a-e2fddb2a52f6_terseLabel_en-US" xlink:label="lab_good_TaylorsvilleUtahOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Taylorsville, Utah Office Building </link:label>

<link:label id="lab_good_TaylorsvilleUtahOfficeBuildingMember_label_en-US" xlink:label="lab_good_TaylorsvilleUtahOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Taylorsville, Utah Office Building [Member] </link:label>

<link:label id="lab_good_TaylorsvilleUtahOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_TaylorsvilleUtahOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Taylorsville, Utah Office Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_TaylorsvilleUtahOfficeBuildingMember" xlink:href="good-20221231.xsd#good_TaylorsvilleUtahOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_TaylorsvilleUtahOfficeBuildingMember" xlink:to="lab_good_TaylorsvilleUtahOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_BollingbrookIllinoisIndustrialBuildingMember_ec5c5e1e-eb14-46b8-9617-f51c3feb43c6_terseLabel_en-US" xlink:label="lab_good_BollingbrookIllinoisIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Bollingbrook, Illinois Industrial Building </link:label>

<link:label id="lab_good_BollingbrookIllinoisIndustrialBuildingMember_label_en-US" xlink:label="lab_good_BollingbrookIllinoisIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Bollingbrook Illinois Industrial Building [Member] </link:label>

<link:label id="lab_good_BollingbrookIllinoisIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_BollingbrookIllinoisIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Bollingbrook Illinois industrial building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BollingbrookIllinoisIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_BollingbrookIllinoisIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BollingbrookIllinoisIndustrialBuildingMember" xlink:to="lab_good_BollingbrookIllinoisIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfDerivativeInstrumentsTextBlock_54993aca-bdef-4867-97b5-685838d49402_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfDerivativeInstrumentsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Derivative Instruments </link:label>

<link:label id="lab_us-gaap_ScheduleOfDerivativeInstrumentsTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfDerivativeInstrumentsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Derivative Instruments [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDerivativeInstrumentsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfDerivativeInstrumentsTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfDerivativeInstrumentsTextBlock" xlink:to="lab_us-gaap_ScheduleOfDerivativeInstrumentsTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NonoperatingIncomeExpenseAbstract_46c2c9b6-bb57-4a4e-9745-d351f6e85ab2_terseLabel_en-US" xlink:label="lab_us-gaap_NonoperatingIncomeExpenseAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other income (expense) </link:label>

<link:label id="lab_us-gaap_NonoperatingIncomeExpenseAbstract_label_en-US" xlink:label="lab_us-gaap_NonoperatingIncomeExpenseAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Nonoperating Income (Expense) [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpenseAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NonoperatingIncomeExpenseAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="lab_us-gaap_NonoperatingIncomeExpenseAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_A600SeriesGCumulativeRedeemablePreferredStockMember_d5c540d2-74f8-4be3-b399-8e021b746c6c_terseLabel_en-US" xlink:label="lab_good_A600SeriesGCumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 6.00% Series G Cumulative Redeemable Preferred Stock </link:label>

<link:label id="lab_good_A600SeriesGCumulativeRedeemablePreferredStockMember_label_en-US" xlink:label="lab_good_A600SeriesGCumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 6.00% Series G Cumulative Redeemable Preferred Stock [Member] </link:label>

<link:label id="lab_good_A600SeriesGCumulativeRedeemablePreferredStockMember_documentation_en-US" xlink:label="lab_good_A600SeriesGCumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 6.00% Series G Cumulative Redeemable Preferred Stock </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_A600SeriesGCumulativeRedeemablePreferredStockMember" xlink:href="good-20221231.xsd#good_A600SeriesGCumulativeRedeemablePreferredStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_A600SeriesGCumulativeRedeemablePreferredStockMember" xlink:to="lab_good_A600SeriesGCumulativeRedeemablePreferredStockMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_IndividualMember_191a1ab3-d68d-43cb-a954-ff43cda197b6_terseLabel_en-US" xlink:label="lab_us-gaap_IndividualMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Counterparty </link:label>

<link:label id="lab_us-gaap_IndividualMember_label_en-US" xlink:label="lab_us-gaap_IndividualMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Individual Counterparty [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndividualMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IndividualMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IndividualMember" xlink:to="lab_us-gaap_IndividualMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_WichitaKansasOfficeBuildingMember_464d4c06-44af-4d83-b1d5-7f0065176a5e_terseLabel_en-US" xlink:label="lab_good_WichitaKansasOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wichita, Kansas Office Building </link:label>

<link:label id="lab_good_WichitaKansasOfficeBuildingMember_label_en-US" xlink:label="lab_good_WichitaKansasOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wichita Kansas Office Building [Member] </link:label>

<link:label id="lab_good_WichitaKansasOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_WichitaKansasOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wichita Kansas office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_WichitaKansasOfficeBuildingMember" xlink:href="good-20221231.xsd#good_WichitaKansasOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_WichitaKansasOfficeBuildingMember" xlink:to="lab_good_WichitaKansasOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_ScheduleOfFutureMinimumRentalIncomeForOperatingLeasesTableTableTextBlock_997812dd-2724-4e24-b160-da96f9a295c7_terseLabel_en-US" xlink:label="lab_good_ScheduleOfFutureMinimumRentalIncomeForOperatingLeasesTableTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Summary of Estimated Aggregate Rental Income </link:label>

<link:label id="lab_good_ScheduleOfFutureMinimumRentalIncomeForOperatingLeasesTableTableTextBlock_label_en-US" xlink:label="lab_good_ScheduleOfFutureMinimumRentalIncomeForOperatingLeasesTableTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Future Minimum Rental Income For Operating Leases Table [Table Text Block] </link:label>

<link:label id="lab_good_ScheduleOfFutureMinimumRentalIncomeForOperatingLeasesTableTableTextBlock_documentation_en-US" xlink:label="lab_good_ScheduleOfFutureMinimumRentalIncomeForOperatingLeasesTableTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Future Minimum Rental Income For Operating Leases Table [Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ScheduleOfFutureMinimumRentalIncomeForOperatingLeasesTableTableTextBlock" xlink:href="good-20221231.xsd#good_ScheduleOfFutureMinimumRentalIncomeForOperatingLeasesTableTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ScheduleOfFutureMinimumRentalIncomeForOperatingLeasesTableTableTextBlock" xlink:to="lab_good_ScheduleOfFutureMinimumRentalIncomeForOperatingLeasesTableTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_83364507-47b9-4636-94da-27087b861aae_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of credit facility, maximum additional amount drawn </link:label>

<link:label id="lab_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of Credit Facility, Remaining Borrowing Capacity </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:to="lab_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:type="arc" order="1"/>

<link:label id="lab_good_VariableRateLineofCreditMember_62b4a156-c4b9-4ed6-afee-7118e7145424_terseLabel_en-US" xlink:label="lab_good_VariableRateLineofCreditMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable rate revolving credit facility </link:label>

<link:label id="lab_good_VariableRateLineofCreditMember_label_en-US" xlink:label="lab_good_VariableRateLineofCreditMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate Line of Credit [Member] </link:label>

<link:label id="lab_good_VariableRateLineofCreditMember_documentation_en-US" xlink:label="lab_good_VariableRateLineofCreditMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate Line of Credit [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_VariableRateLineofCreditMember" xlink:href="good-20221231.xsd#good_VariableRateLineofCreditMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_VariableRateLineofCreditMember" xlink:to="lab_good_VariableRateLineofCreditMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_NewOrleansLouisianaIndustrialBuildingMember_44f36ace-fee3-4411-878d-4ff74053ac5e_terseLabel_en-US" xlink:label="lab_good_NewOrleansLouisianaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Orleans, Louisiana Industrial Building </link:label>

<link:label id="lab_good_NewOrleansLouisianaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_NewOrleansLouisianaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Orleans, Louisiana Industrial Building [Member] </link:label>

<link:label id="lab_good_NewOrleansLouisianaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_NewOrleansLouisianaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Orleans, Louisiana Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NewOrleansLouisianaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_NewOrleansLouisianaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NewOrleansLouisianaIndustrialBuildingMember" xlink:to="lab_good_NewOrleansLouisianaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CreditFacilityAxis_ddd12494-c4b3-4afe-8104-0bce9b1cfbff_terseLabel_en-US" xlink:label="lab_us-gaap_CreditFacilityAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Credit Facility [Axis] </link:label>

<link:label id="lab_us-gaap_CreditFacilityAxis_label_en-US" xlink:label="lab_us-gaap_CreditFacilityAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Credit Facility [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CreditFacilityAxis" xlink:to="lab_us-gaap_CreditFacilityAxis" xlink:type="arc" order="1"/>

<link:label id="lab_good_LexingtonNorthCarolinaCommercialAndWarehouseBuildingMember_0748454a-f241-4e70-9693-695766b3e379_terseLabel_en-US" xlink:label="lab_good_LexingtonNorthCarolinaCommercialAndWarehouseBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lexington, North Carolina Industrial Building </link:label>

<link:label id="lab_good_LexingtonNorthCarolinaCommercialAndWarehouseBuildingMember_label_en-US" xlink:label="lab_good_LexingtonNorthCarolinaCommercialAndWarehouseBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lexington North Carolina Commercial And Warehouse Building [Member] </link:label>

<link:label id="lab_good_LexingtonNorthCarolinaCommercialAndWarehouseBuildingMember_documentation_en-US" xlink:label="lab_good_LexingtonNorthCarolinaCommercialAndWarehouseBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lexington North Carolina commercial and warehouse building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_LexingtonNorthCarolinaCommercialAndWarehouseBuildingMember" xlink:href="good-20221231.xsd#good_LexingtonNorthCarolinaCommercialAndWarehouseBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_LexingtonNorthCarolinaCommercialAndWarehouseBuildingMember" xlink:to="lab_good_LexingtonNorthCarolinaCommercialAndWarehouseBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_AdditionsAbstract_ff670d3b-ac73-47ba-a263-3761fbd91700_terseLabel_en-US" xlink:label="lab_good_AdditionsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Additions: </link:label>

<link:label id="lab_good_AdditionsAbstract_label_en-US" xlink:label="lab_good_AdditionsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Additions [Abstract] </link:label>

<link:label id="lab_good_AdditionsAbstract_documentation_en-US" xlink:label="lab_good_AdditionsAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Additions. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AdditionsAbstract" xlink:href="good-20221231.xsd#good_AdditionsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AdditionsAbstract" xlink:to="lab_good_AdditionsAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_ExpectedLeaseUpPeriod_6b02c985-1c1a-479a-a238-c3c2e8cbc1c2_terseLabel_en-US" xlink:label="lab_good_ExpectedLeaseUpPeriod" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Expected lease up period for estimating carrying costs </link:label>

<link:label id="lab_good_ExpectedLeaseUpPeriod_label_en-US" xlink:label="lab_good_ExpectedLeaseUpPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Expected Lease Up Period </link:label>

<link:label id="lab_good_ExpectedLeaseUpPeriod_documentation_en-US" xlink:label="lab_good_ExpectedLeaseUpPeriod" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Expected lease up period. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ExpectedLeaseUpPeriod" xlink:href="good-20221231.xsd#good_ExpectedLeaseUpPeriod"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ExpectedLeaseUpPeriod" xlink:to="lab_good_ExpectedLeaseUpPeriod" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_EquityAbstract_a2818c70-cc87-4bb0-85f6-55d600c47b19_terseLabel_en-US" xlink:label="lab_us-gaap_EquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equity [Abstract] </link:label>

<link:label id="lab_us-gaap_EquityAbstract_label_en-US" xlink:label="lab_us-gaap_EquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equity [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EquityAbstract" xlink:to="lab_us-gaap_EquityAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_ConyersGeorgiaOfficeBuildingMember_bd070e8c-f36f-484c-81dc-7aa364722756_terseLabel_en-US" xlink:label="lab_good_ConyersGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Conyers Georgia Office Building </link:label>

<link:label id="lab_good_ConyersGeorgiaOfficeBuildingMember_label_en-US" xlink:label="lab_good_ConyersGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Conyers Georgia Office Building [Member] </link:label>

<link:label id="lab_good_ConyersGeorgiaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_ConyersGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Conyers Georgia office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ConyersGeorgiaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_ConyersGeorgiaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ConyersGeorgiaOfficeBuildingMember" xlink:to="lab_good_ConyersGeorgiaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SubsequentEventTable_75bdd21e-1d3f-4131-9c18-5e6bff412dc3_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsequent Event [Table] </link:label>

<link:label id="lab_us-gaap_SubsequentEventTable_label_en-US" xlink:label="lab_us-gaap_SubsequentEventTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsequent Event [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventTable" xlink:to="lab_us-gaap_SubsequentEventTable" xlink:type="arc" order="1"/>

<link:label id="lab_good_EggHarborNewJerseyOfficeBuildingMember_eebad8c1-118c-4349-a30e-476f9bbebec9_terseLabel_en-US" xlink:label="lab_good_EggHarborNewJerseyOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Egg Harbor, New Jersey Office Building </link:label>

<link:label id="lab_good_EggHarborNewJerseyOfficeBuildingMember_label_en-US" xlink:label="lab_good_EggHarborNewJerseyOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Egg Harbor New Jersey Office Building [Member] </link:label>

<link:label id="lab_good_EggHarborNewJerseyOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_EggHarborNewJerseyOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Egg Harbor New Jersey Office Building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_EggHarborNewJerseyOfficeBuildingMember" xlink:href="good-20221231.xsd#good_EggHarborNewJerseyOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_EggHarborNewJerseyOfficeBuildingMember" xlink:to="lab_good_EggHarborNewJerseyOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberofExecutiveOfficers_abb3859f-82a6-40ad-89d3-f13188f91b0b_terseLabel_en-US" xlink:label="lab_good_NumberofExecutiveOfficers" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of executive officers </link:label>

<link:label id="lab_good_NumberofExecutiveOfficers_label_en-US" xlink:label="lab_good_NumberofExecutiveOfficers" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Executive Officers </link:label>

<link:label id="lab_good_NumberofExecutiveOfficers_documentation_en-US" xlink:label="lab_good_NumberofExecutiveOfficers" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Executive Officers </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberofExecutiveOfficers" xlink:href="good-20221231.xsd#good_NumberofExecutiveOfficers"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberofExecutiveOfficers" xlink:to="lab_good_NumberofExecutiveOfficers" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityTaxIdentificationNumber_471dfcef-dc0f-45d4-8687-02969b3fe511_terseLabel_en-US" xlink:label="lab_dei_EntityTaxIdentificationNumber" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Tax Identification Number </link:label>

<link:label id="lab_dei_EntityTaxIdentificationNumber_label_en-US" xlink:label="lab_dei_EntityTaxIdentificationNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Tax Identification Number </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityTaxIdentificationNumber"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityTaxIdentificationNumber" xlink:to="lab_dei_EntityTaxIdentificationNumber" xlink:type="arc" order="1"/>

<link:label id="lab_good_MaitlandFloridaOfficeBuildingThreeMember_bd75d36f-5564-4ed5-ac79-f9e351ec628b_terseLabel_en-US" xlink:label="lab_good_MaitlandFloridaOfficeBuildingThreeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Maitland Florida Office Building Three </link:label>

<link:label id="lab_good_MaitlandFloridaOfficeBuildingThreeMember_label_en-US" xlink:label="lab_good_MaitlandFloridaOfficeBuildingThreeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Maitland Florida Office Building Three [Member] </link:label>

<link:label id="lab_good_MaitlandFloridaOfficeBuildingThreeMember_documentation_en-US" xlink:label="lab_good_MaitlandFloridaOfficeBuildingThreeMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Maitland Florida Office Building Three [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_MaitlandFloridaOfficeBuildingThreeMember" xlink:href="good-20221231.xsd#good_MaitlandFloridaOfficeBuildingThreeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_MaitlandFloridaOfficeBuildingThreeMember" xlink:to="lab_good_MaitlandFloridaOfficeBuildingThreeMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_AggregateUndiscountedObligationOnProperties_e1af105e-98f6-4f4e-bf32-e812279e647c_terseLabel_en-US" xlink:label="lab_good_AggregateUndiscountedObligationOnProperties" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate undiscounted obligation on properties </link:label>

<link:label id="lab_good_AggregateUndiscountedObligationOnProperties_label_en-US" xlink:label="lab_good_AggregateUndiscountedObligationOnProperties" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate Undiscounted Obligation On Properties </link:label>

<link:label id="lab_good_AggregateUndiscountedObligationOnProperties_documentation_en-US" xlink:label="lab_good_AggregateUndiscountedObligationOnProperties" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate undiscounted obligation on properties. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AggregateUndiscountedObligationOnProperties" xlink:href="good-20221231.xsd#good_AggregateUndiscountedObligationOnProperties"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AggregateUndiscountedObligationOnProperties" xlink:to="lab_good_AggregateUndiscountedObligationOnProperties" xlink:type="arc" order="1"/>

<link:label id="lab_good_OrangeCityIowaOfficeAndWarehouseBuildingMember_d8eae417-0fe5-4616-b62f-e16caed78cae_terseLabel_en-US" xlink:label="lab_good_OrangeCityIowaOfficeAndWarehouseBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Orange City, Iowa Industrial Building </link:label>

<link:label id="lab_good_OrangeCityIowaOfficeAndWarehouseBuildingMember_label_en-US" xlink:label="lab_good_OrangeCityIowaOfficeAndWarehouseBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Orange City Iowa Office And Warehouse Building [Member] </link:label>

<link:label id="lab_good_OrangeCityIowaOfficeAndWarehouseBuildingMember_documentation_en-US" xlink:label="lab_good_OrangeCityIowaOfficeAndWarehouseBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Orange City Iowa office and warehouse building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_OrangeCityIowaOfficeAndWarehouseBuildingMember" xlink:href="good-20221231.xsd#good_OrangeCityIowaOfficeAndWarehouseBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_OrangeCityIowaOfficeAndWarehouseBuildingMember" xlink:to="lab_good_OrangeCityIowaOfficeAndWarehouseBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_DecaturGeorgiaOfficeBuildingOneMember_65124522-f7e3-4f03-8ece-6a770cafe5ae_terseLabel_en-US" xlink:label="lab_good_DecaturGeorgiaOfficeBuildingOneMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Decatur, Georgia Medical Office Building </link:label>

<link:label id="lab_good_DecaturGeorgiaOfficeBuildingOneMember_label_en-US" xlink:label="lab_good_DecaturGeorgiaOfficeBuildingOneMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Decatur Georgia Office Building One [Member] </link:label>

<link:label id="lab_good_DecaturGeorgiaOfficeBuildingOneMember_documentation_en-US" xlink:label="lab_good_DecaturGeorgiaOfficeBuildingOneMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Decatur Georgia office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DecaturGeorgiaOfficeBuildingOneMember" xlink:href="good-20221231.xsd#good_DecaturGeorgiaOfficeBuildingOneMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DecaturGeorgiaOfficeBuildingOneMember" xlink:to="lab_good_DecaturGeorgiaOfficeBuildingOneMember" xlink:type="arc" order="1"/>

<link:label id="lab_srt_ConsolidatedEntitiesDomain_daca792e-6711-4b99-9144-cbb2e65a97ed_terseLabel_en-US" xlink:label="lab_srt_ConsolidatedEntitiesDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Consolidated Entities [Domain] </link:label>

<link:label id="lab_srt_ConsolidatedEntitiesDomain_label_en-US" xlink:label="lab_srt_ConsolidatedEntitiesDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Consolidated Entities [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidatedEntitiesDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ConsolidatedEntitiesDomain" xlink:to="lab_srt_ConsolidatedEntitiesDomain" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SECScheduleIIIRealEstateInvestmentPropertyNet_51523bd2-afa1-4ce1-9650-6e5290a57c10_totalLabel_en-US" xlink:label="lab_us-gaap_SECScheduleIIIRealEstateInvestmentPropertyNet" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net real estate </link:label>

<link:label id="lab_us-gaap_SECScheduleIIIRealEstateInvestmentPropertyNet_label_en-US" xlink:label="lab_us-gaap_SECScheduleIIIRealEstateInvestmentPropertyNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Investment Property, Net </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SECScheduleIIIRealEstateInvestmentPropertyNet" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SECScheduleIIIRealEstateInvestmentPropertyNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SECScheduleIIIRealEstateInvestmentPropertyNet" xlink:to="lab_us-gaap_SECScheduleIIIRealEstateInvestmentPropertyNet" xlink:type="arc" order="1"/>

<link:label id="lab_good_SeriesECumulativeRedeemablePreferredStockMember_b2bd4f84-3177-4c8e-86c3-9b5624880a9e_terseLabel_en-US" xlink:label="lab_good_SeriesECumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series E Cumulative Redeemable Preferred Stock </link:label>

<link:label id="lab_good_SeriesECumulativeRedeemablePreferredStockMember_label_en-US" xlink:label="lab_good_SeriesECumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series E Cumulative Redeemable Preferred Stock [Member] </link:label>

<link:label id="lab_good_SeriesECumulativeRedeemablePreferredStockMember_documentation_en-US" xlink:label="lab_good_SeriesECumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series E Cumulative Redeemable Preferred Stock [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SeriesECumulativeRedeemablePreferredStockMember" xlink:href="good-20221231.xsd#good_SeriesECumulativeRedeemablePreferredStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SeriesECumulativeRedeemablePreferredStockMember" xlink:to="lab_good_SeriesECumulativeRedeemablePreferredStockMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_SummaryOfPropertiesAcquiredTableTextBlock_f45c3849-c27b-45fd-8678-fd957f4cbf45_terseLabel_en-US" xlink:label="lab_good_SummaryOfPropertiesAcquiredTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Summary of Properties Acquired </link:label>

<link:label id="lab_good_SummaryOfPropertiesAcquiredTableTextBlock_label_en-US" xlink:label="lab_good_SummaryOfPropertiesAcquiredTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Summary Of Properties Acquired [Table Text Block] </link:label>

<link:label id="lab_good_SummaryOfPropertiesAcquiredTableTextBlock_documentation_en-US" xlink:label="lab_good_SummaryOfPropertiesAcquiredTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Summary of properties acquired. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SummaryOfPropertiesAcquiredTableTextBlock" xlink:href="good-20221231.xsd#good_SummaryOfPropertiesAcquiredTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SummaryOfPropertiesAcquiredTableTextBlock" xlink:to="lab_good_SummaryOfPropertiesAcquiredTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_72a405d0-9b07-49c6-aaf1-2fb1583e6e0b_totalLabel_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net increase (decrease) in cash, cash equivalents, and restricted cash </link:label>

<link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_label_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:type="arc" order="1"/>

<link:label id="lab_good_AmortizationOfDeferredRentAssetAndLiabilityNet_fa2f929b-b44e-4865-b242-7f4daec36e64_terseLabel_en-US" xlink:label="lab_good_AmortizationOfDeferredRentAssetAndLiabilityNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of deferred rent asset and liability, net </link:label>

<link:label id="lab_good_AmortizationOfDeferredRentAssetAndLiabilityNet_label_en-US" xlink:label="lab_good_AmortizationOfDeferredRentAssetAndLiabilityNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization Of Deferred Rent Asset And Liability Net </link:label>

<link:label id="lab_good_AmortizationOfDeferredRentAssetAndLiabilityNet_documentation_en-US" xlink:label="lab_good_AmortizationOfDeferredRentAssetAndLiabilityNet" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of deferred rent asset and liability, net. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AmortizationOfDeferredRentAssetAndLiabilityNet" xlink:href="good-20221231.xsd#good_AmortizationOfDeferredRentAssetAndLiabilityNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AmortizationOfDeferredRentAssetAndLiabilityNet" xlink:to="lab_good_AmortizationOfDeferredRentAssetAndLiabilityNet" xlink:type="arc" order="1"/>

<link:label id="lab_good_DentonTexasIndustrialBuildingMember_d8ea065d-e868-45ea-b261-3aba993a5e28_terseLabel_en-US" xlink:label="lab_good_DentonTexasIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Denton, Texas Industrial Building </link:label>

<link:label id="lab_good_DentonTexasIndustrialBuildingMember_label_en-US" xlink:label="lab_good_DentonTexasIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Denton, Texas Industrial Building [Member] </link:label>

<link:label id="lab_good_DentonTexasIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_DentonTexasIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Denton, Texas Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DentonTexasIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_DentonTexasIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DentonTexasIndustrialBuildingMember" xlink:to="lab_good_DentonTexasIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_FindleyOhioIndustrialBuildingMember_24d9127b-5275-469e-aa3b-43c28bbc4c64_terseLabel_en-US" xlink:label="lab_good_FindleyOhioIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Findley, Ohio Industrial Building </link:label>

<link:label id="lab_good_FindleyOhioIndustrialBuildingMember_label_en-US" xlink:label="lab_good_FindleyOhioIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Findley, Ohio Industrial Building [Member] </link:label>

<link:label id="lab_good_FindleyOhioIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_FindleyOhioIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Findley, Ohio Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_FindleyOhioIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_FindleyOhioIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_FindleyOhioIndustrialBuildingMember" xlink:to="lab_good_FindleyOhioIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_SanAntonioTexasFlexibleOfficeBuildingMember_1fb8ad22-9066-47ad-8619-e3c7a2ddda45_terseLabel_en-US" xlink:label="lab_good_SanAntonioTexasFlexibleOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> San Antonio, Texas Office Building </link:label>

<link:label id="lab_good_SanAntonioTexasFlexibleOfficeBuildingMember_label_en-US" xlink:label="lab_good_SanAntonioTexasFlexibleOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> San Antonio Texas Flexible Office Building [Member] </link:label>

<link:label id="lab_good_SanAntonioTexasFlexibleOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_SanAntonioTexasFlexibleOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> San Antonio Texas flexible office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SanAntonioTexasFlexibleOfficeBuildingMember" xlink:href="good-20221231.xsd#good_SanAntonioTexasFlexibleOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SanAntonioTexasFlexibleOfficeBuildingMember" xlink:to="lab_good_SanAntonioTexasFlexibleOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityCentralIndexKey_9506e40d-b7e6-486a-a3b8-6500a2079fdb_terseLabel_en-US" xlink:label="lab_dei_EntityCentralIndexKey" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Central Index Key </link:label>

<link:label id="lab_dei_EntityCentralIndexKey_label_en-US" xlink:label="lab_dei_EntityCentralIndexKey" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Central Index Key </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityCentralIndexKey"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityCentralIndexKey" xlink:to="lab_dei_EntityCentralIndexKey" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateAbstract_fd71c354-8629-4fdd-b8a8-f7b2bf63af65_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstateAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate [Abstract] </link:label>

<link:label id="lab_us-gaap_RealEstateAbstract_label_en-US" xlink:label="lab_us-gaap_RealEstateAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateAbstract" xlink:to="lab_us-gaap_RealEstateAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RepaymentsOfSecuredDebt_92baef9a-6835-4abf-9668-912f960cc69b_negatedLabel_en-US" xlink:label="lab_us-gaap_RepaymentsOfSecuredDebt" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Principal repayments on mortgage notes payable </link:label>

<link:label id="lab_us-gaap_RepaymentsOfSecuredDebt_c608e713-0930-4826-9e74-c17a7d560532_verboseLabel_en-US" xlink:label="lab_us-gaap_RepaymentsOfSecuredDebt" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt repaid </link:label>

<link:label id="lab_us-gaap_RepaymentsOfSecuredDebt_label_en-US" xlink:label="lab_us-gaap_RepaymentsOfSecuredDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Repayments of Secured Debt </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfSecuredDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RepaymentsOfSecuredDebt"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RepaymentsOfSecuredDebt" xlink:to="lab_us-gaap_RepaymentsOfSecuredDebt" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_2101946d-e447-4cbd-92f9-060c91197249_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets by Major Class [Axis] </link:label>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets by Major Class [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateInvestmentPropertyAtCostAbstract_51098693-ac2e-489f-9033-9a18f32e1105_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstateInvestmentPropertyAtCostAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real estate: </link:label>

<link:label id="lab_us-gaap_RealEstateInvestmentPropertyAtCostAbstract_label_en-US" xlink:label="lab_us-gaap_RealEstateInvestmentPropertyAtCostAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Investment Property, at Cost [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateInvestmentPropertyAtCostAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateInvestmentPropertyAtCostAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateInvestmentPropertyAtCostAbstract" xlink:to="lab_us-gaap_RealEstateInvestmentPropertyAtCostAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateOtherAcquisitions_6bc03dae-9644-4161-9568-1b558adb34dc_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstateOtherAcquisitions" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Acquisitions during period </link:label>

<link:label id="lab_us-gaap_RealEstateOtherAcquisitions_label_en-US" xlink:label="lab_us-gaap_RealEstateOtherAcquisitions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Other Acquisition </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateOtherAcquisitions" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateOtherAcquisitions"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateOtherAcquisitions" xlink:to="lab_us-gaap_RealEstateOtherAcquisitions" xlink:type="arc" order="1"/>

<link:label id="lab_dei_CityAreaCode_b1612f29-7f98-47f6-84bc-c469780fa766_terseLabel_en-US" xlink:label="lab_dei_CityAreaCode" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> City Area Code </link:label>

<link:label id="lab_dei_CityAreaCode_label_en-US" xlink:label="lab_dei_CityAreaCode" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> City Area Code </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_CityAreaCode"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_CityAreaCode" xlink:to="lab_dei_CityAreaCode" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AssetsAbstract_da7dff81-ba14-4ea5-9a4b-3e5f00b54df7_terseLabel_en-US" xlink:label="lab_us-gaap_AssetsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> ASSETS </link:label>

<link:label id="lab_us-gaap_AssetsAbstract_label_en-US" xlink:label="lab_us-gaap_AssetsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Assets [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsAbstract" xlink:to="lab_us-gaap_AssetsAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_PercentageOfLimitedPartnershipInterestTransferredToBusinessUnit_26b3144b-06b0-4745-9d2f-10688e550c50_terseLabel_en-US" xlink:label="lab_good_PercentageOfLimitedPartnershipInterestTransferredToBusinessUnit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of limited partnership interest transferred to business unit </link:label>

<link:label id="lab_good_PercentageOfLimitedPartnershipInterestTransferredToBusinessUnit_label_en-US" xlink:label="lab_good_PercentageOfLimitedPartnershipInterestTransferredToBusinessUnit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage Of Limited Partnership Interest Transferred To Business Unit </link:label>

<link:label id="lab_good_PercentageOfLimitedPartnershipInterestTransferredToBusinessUnit_documentation_en-US" xlink:label="lab_good_PercentageOfLimitedPartnershipInterestTransferredToBusinessUnit" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of limited partnership interest transferred to business unit. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PercentageOfLimitedPartnershipInterestTransferredToBusinessUnit" xlink:href="good-20221231.xsd#good_PercentageOfLimitedPartnershipInterestTransferredToBusinessUnit"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PercentageOfLimitedPartnershipInterestTransferredToBusinessUnit" xlink:to="lab_good_PercentageOfLimitedPartnershipInterestTransferredToBusinessUnit" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ProceedsFromSaleOfLandHeldforinvestment_ee514f1f-2537-42c5-939f-c28e65f03e10_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromSaleOfLandHeldforinvestment" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from sale of real estate </link:label>

<link:label id="lab_us-gaap_ProceedsFromSaleOfLandHeldforinvestment_label_en-US" xlink:label="lab_us-gaap_ProceedsFromSaleOfLandHeldforinvestment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from Sale of Land Held-for-investment </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfLandHeldforinvestment" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromSaleOfLandHeldforinvestment"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromSaleOfLandHeldforinvestment" xlink:to="lab_us-gaap_ProceedsFromSaleOfLandHeldforinvestment" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SubsidiarySaleOfStockAxis_decfdcee-034c-4e47-82e0-56c347b9bca3_terseLabel_en-US" xlink:label="lab_us-gaap_SubsidiarySaleOfStockAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale of Stock [Axis] </link:label>

<link:label id="lab_us-gaap_SubsidiarySaleOfStockAxis_label_en-US" xlink:label="lab_us-gaap_SubsidiarySaleOfStockAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale of Stock [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis" xlink:to="lab_us-gaap_SubsidiarySaleOfStockAxis" xlink:type="arc" order="1"/>

<link:label id="lab_good_PaymentsforTenantInducement_30247408-8cf2-4602-a594-0da852f2819f_negatedLabel_en-US" xlink:label="lab_good_PaymentsforTenantInducement" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tenant inducement payments </link:label>

<link:label id="lab_good_PaymentsforTenantInducement_label_en-US" xlink:label="lab_good_PaymentsforTenantInducement" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments for Tenant Inducement </link:label>

<link:label id="lab_good_PaymentsforTenantInducement_documentation_en-US" xlink:label="lab_good_PaymentsforTenantInducement" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments for Tenant Inducement </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PaymentsforTenantInducement" xlink:href="good-20221231.xsd#good_PaymentsforTenantInducement"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PaymentsforTenantInducement" xlink:to="lab_good_PaymentsforTenantInducement" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_EarningsPerSharePolicyTextBlock_8838c07e-587f-41f6-a3ef-6ad42029efd6_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerSharePolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> (Loss) Earnings per Share of Common Stock </link:label>

<link:label id="lab_us-gaap_EarningsPerSharePolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_EarningsPerSharePolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings Per Share, Policy [Policy Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerSharePolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerSharePolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerSharePolicyTextBlock" xlink:to="lab_us-gaap_EarningsPerSharePolicyTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_c79db9f2-1ffc-406c-b17f-b6576d67b7c4_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2023 </link:label>

<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Maturity, Year One </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:type="arc" order="1"/>

<link:label id="lab_good_BurnsvilleMinnesotaOfficeBuildingMember_8a879e00-56a5-4539-a137-f61d29d73f37_terseLabel_en-US" xlink:label="lab_good_BurnsvilleMinnesotaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Burnsville, Minnesota Office Building </link:label>

<link:label id="lab_good_BurnsvilleMinnesotaOfficeBuildingMember_label_en-US" xlink:label="lab_good_BurnsvilleMinnesotaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Burnsville Minnesota Office Building [Member] </link:label>

<link:label id="lab_good_BurnsvilleMinnesotaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_BurnsvilleMinnesotaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Burnsville Minnesota office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BurnsvilleMinnesotaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_BurnsvilleMinnesotaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BurnsvilleMinnesotaOfficeBuildingMember" xlink:to="lab_good_BurnsvilleMinnesotaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_VariableRateAxis_ceac2c07-6b3c-4054-ab8c-4a05fb3e5289_terseLabel_en-US" xlink:label="lab_us-gaap_VariableRateAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate [Axis] </link:label>

<link:label id="lab_us-gaap_VariableRateAxis_label_en-US" xlink:label="lab_us-gaap_VariableRateAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_VariableRateAxis" xlink:to="lab_us-gaap_VariableRateAxis" xlink:type="arc" order="1"/>

<link:label id="lab_good_ColumbiaSouthCarolinaMember_d2fba9be-5925-4de0-9811-1f4d0b20bb41_terseLabel_en-US" xlink:label="lab_good_ColumbiaSouthCarolinaMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbia, South Carolina </link:label>

<link:label id="lab_good_ColumbiaSouthCarolinaMember_label_en-US" xlink:label="lab_good_ColumbiaSouthCarolinaMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbia, South Carolina [Member] </link:label>

<link:label id="lab_good_ColumbiaSouthCarolinaMember_documentation_en-US" xlink:label="lab_good_ColumbiaSouthCarolinaMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Columbia, South Carolina </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ColumbiaSouthCarolinaMember" xlink:href="good-20221231.xsd#good_ColumbiaSouthCarolinaMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ColumbiaSouthCarolinaMember" xlink:to="lab_good_ColumbiaSouthCarolinaMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_MonroeMichiganIndustrialBuildingOneMember_6aec4399-1fb8-46e1-889d-8473a2430f24_terseLabel_en-US" xlink:label="lab_good_MonroeMichiganIndustrialBuildingOneMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Monroe, Michigan Industrial Building </link:label>

<link:label id="lab_good_MonroeMichiganIndustrialBuildingOneMember_label_en-US" xlink:label="lab_good_MonroeMichiganIndustrialBuildingOneMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Monroe, Michigan Industrial Building One [Member] </link:label>

<link:label id="lab_good_MonroeMichiganIndustrialBuildingOneMember_documentation_en-US" xlink:label="lab_good_MonroeMichiganIndustrialBuildingOneMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Monroe, Michigan Industrial Building One [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_MonroeMichiganIndustrialBuildingOneMember" xlink:href="good-20221231.xsd#good_MonroeMichiganIndustrialBuildingOneMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_MonroeMichiganIndustrialBuildingOneMember" xlink:to="lab_good_MonroeMichiganIndustrialBuildingOneMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_RaleighNorthCarolinaOfficeBuildingMember_13254837-25e8-4e5a-b470-fc55c311c1f4_terseLabel_en-US" xlink:label="lab_good_RaleighNorthCarolinaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Raleigh, North Carolina Office Building </link:label>

<link:label id="lab_good_RaleighNorthCarolinaOfficeBuildingMember_label_en-US" xlink:label="lab_good_RaleighNorthCarolinaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Raleigh North Carolina Office Building [Member] </link:label>

<link:label id="lab_good_RaleighNorthCarolinaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_RaleighNorthCarolinaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Raleigh North Carolina office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_RaleighNorthCarolinaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_RaleighNorthCarolinaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_RaleighNorthCarolinaOfficeBuildingMember" xlink:to="lab_good_RaleighNorthCarolinaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_IncentiveFeeCredit_b62847b4-227e-4833-ba21-3f2ae287f214_negatedLabel_en-US" xlink:label="lab_good_IncentiveFeeCredit" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Incentive fee waiver </link:label>

<link:label id="lab_good_IncentiveFeeCredit_label_en-US" xlink:label="lab_good_IncentiveFeeCredit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Incentive Fee Credit </link:label>

<link:label id="lab_good_IncentiveFeeCredit_documentation_en-US" xlink:label="lab_good_IncentiveFeeCredit" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Incentive Fee Credit </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_IncentiveFeeCredit" xlink:href="good-20221231.xsd#good_IncentiveFeeCredit"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_IncentiveFeeCredit" xlink:to="lab_good_IncentiveFeeCredit" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_786a1369-a274-4316-bd67-98aeab52b7df_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> (Decrease) increase in other liabilities </link:label>

<link:label id="lab_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Other Operating Liabilities </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInOtherOperatingLiabilities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:to="lab_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_EscrowDeposit_c0928e57-bbde-473f-af01-a10812da9d99_terseLabel_en-US" xlink:label="lab_us-gaap_EscrowDeposit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Funds held in escrow </link:label>

<link:label id="lab_us-gaap_EscrowDeposit_label_en-US" xlink:label="lab_us-gaap_EscrowDeposit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Escrow Deposit </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EscrowDeposit" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EscrowDeposit"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EscrowDeposit" xlink:to="lab_us-gaap_EscrowDeposit" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_881e814c-8d27-4e5a-a6d9-fdf00315e4d2_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2023 </link:label>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Asset, Expected Amortization, Year One </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_34a812a0-dbde-4966-b02d-d8c7d5c6d645_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Basic and Diluted (Loss) Earnings Per Share of Common Stock </link:label>

<link:label id="lab_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_SeriesEPreferredStockATMProgramMember_a6014545-99df-4fa5-80f3-c9ec3686090c_terseLabel_en-US" xlink:label="lab_good_SeriesEPreferredStockATMProgramMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series E Preferred Stock ATM Program </link:label>

<link:label id="lab_good_SeriesEPreferredStockATMProgramMember_label_en-US" xlink:label="lab_good_SeriesEPreferredStockATMProgramMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series E Preferred Stock ATM Program [Member] </link:label>

<link:label id="lab_good_SeriesEPreferredStockATMProgramMember_documentation_en-US" xlink:label="lab_good_SeriesEPreferredStockATMProgramMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series E Preferred Stock ATM Program [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SeriesEPreferredStockATMProgramMember" xlink:href="good-20221231.xsd#good_SeriesEPreferredStockATMProgramMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SeriesEPreferredStockATMProgramMember" xlink:to="lab_good_SeriesEPreferredStockATMProgramMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_749e649e-db00-4aeb-8b99-06e652ce4afb_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of credit at an interest rate </link:label>

<link:label id="lab_us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of Credit Facility, Interest Rate at Period End </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:to="lab_us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:type="arc" order="1"/>

<link:label id="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAccumulatedDepreciation_d92fd8d8-0a4d-4adc-898f-3e9ed888aedb_verboseLabel_en-US" xlink:label="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAccumulatedDepreciation" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real estate held for sale, accumulated depreciation </link:label>

<link:label id="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAccumulatedDepreciation_label_en-US" xlink:label="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAccumulatedDepreciation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Group Including Discontinued Operation Real Estate Investment Property Accumulated Depreciation </link:label>

<link:label id="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAccumulatedDepreciation_documentation_en-US" xlink:label="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAccumulatedDepreciation" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal group including discontinued operation real estate investment property accumulated depreciation. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAccumulatedDepreciation" xlink:href="good-20221231.xsd#good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAccumulatedDepreciation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAccumulatedDepreciation" xlink:to="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAccumulatedDepreciation" xlink:type="arc" order="1"/>

<link:label id="lab_good_LeasingCostsMember_b3809457-c4ed-4e73-90ad-71bbf7d80dcc_terseLabel_en-US" xlink:label="lab_good_LeasingCostsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Leasing Costs </link:label>

<link:label id="lab_good_LeasingCostsMember_label_en-US" xlink:label="lab_good_LeasingCostsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Leasing Costs [Member] </link:label>

<link:label id="lab_good_LeasingCostsMember_documentation_en-US" xlink:label="lab_good_LeasingCostsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Leasing cost. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_LeasingCostsMember" xlink:href="good-20221231.xsd#good_LeasingCostsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_LeasingCostsMember" xlink:to="lab_good_LeasingCostsMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_69b0d741-7d89-47b4-8828-083fae0af951_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Stockholders' Equity [Roll Forward] </link:label>

<link:label id="lab_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Stockholders' Equity [Roll Forward] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="lab_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_00ebc52a-4305-4f70-ac45-71630a13ec9c_totalLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total anticipated lease payments </link:label>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, to be Paid </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ProfitLoss_b78a0a14-239f-4973-b4b5-c26b616b3f6a_totalLabel_en-US" xlink:label="lab_us-gaap_ProfitLoss" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net income </link:label>

<link:label id="lab_us-gaap_ProfitLoss_f0c433e8-9aae-412b-b9c7-2063610a9bae_terseLabel_en-US" xlink:label="lab_us-gaap_ProfitLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net income </link:label>

<link:label id="lab_us-gaap_ProfitLoss_0ca6dda2-54ae-4b46-b95e-b55ff3f9a754_verboseLabel_en-US" xlink:label="lab_us-gaap_ProfitLoss" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net income </link:label>

<link:label id="lab_us-gaap_ProfitLoss_label_en-US" xlink:label="lab_us-gaap_ProfitLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Income (Loss), Including Portion Attributable to Noncontrolling Interest </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProfitLoss"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProfitLoss" xlink:to="lab_us-gaap_ProfitLoss" xlink:type="arc" order="1"/>

<link:label id="lab_good_LongTermCapitalGainsMember_632a6d81-aeec-4d62-ab85-c24e69219544_terseLabel_en-US" xlink:label="lab_good_LongTermCapitalGainsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Capital Gains </link:label>

<link:label id="lab_good_LongTermCapitalGainsMember_label_en-US" xlink:label="lab_good_LongTermCapitalGainsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long Term Capital Gains [Member] </link:label>

<link:label id="lab_good_LongTermCapitalGainsMember_documentation_en-US" xlink:label="lab_good_LongTermCapitalGainsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long Term Capital Gains [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_LongTermCapitalGainsMember" xlink:href="good-20221231.xsd#good_LongTermCapitalGainsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_LongTermCapitalGainsMember" xlink:to="lab_good_LongTermCapitalGainsMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityAddressPostalZipCode_9a48c2e8-7cea-48b2-9ef7-1f0a723d754b_terseLabel_en-US" xlink:label="lab_dei_EntityAddressPostalZipCode" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, Postal Zip Code </link:label>

<link:label id="lab_dei_EntityAddressPostalZipCode_label_en-US" xlink:label="lab_dei_EntityAddressPostalZipCode" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, Postal Zip Code </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressPostalZipCode"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityAddressPostalZipCode" xlink:to="lab_dei_EntityAddressPostalZipCode" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AreaOfRealEstateProperty_ac875c01-a010-4d8a-9068-3c895dc1203e_terseLabel_en-US" xlink:label="lab_us-gaap_AreaOfRealEstateProperty" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate Square Footage </link:label>

<link:label id="lab_us-gaap_AreaOfRealEstateProperty_label_en-US" xlink:label="lab_us-gaap_AreaOfRealEstateProperty" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Area of Real Estate Property </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AreaOfRealEstateProperty" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AreaOfRealEstateProperty"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AreaOfRealEstateProperty" xlink:to="lab_us-gaap_AreaOfRealEstateProperty" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_8b86285f-3813-4aa0-b821-6dd72e582d4d_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2024 </link:label>

<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Maturity, Year Two </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_BusinessCombinationsPolicy_5fd11032-16d4-4488-a3da-9b0eba66c6d8_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationsPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combinations </link:label>

<link:label id="lab_us-gaap_BusinessCombinationsPolicy_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationsPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combinations Policy [Policy Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationsPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationsPolicy"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationsPolicy" xlink:to="lab_us-gaap_BusinessCombinationsPolicy" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PreferredStockDividendRatePercentage_9cc29901-ba63-4be6-b8b8-7f7ff8afdd7f_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockDividendRatePercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred stock, dividend rate </link:label>

<link:label id="lab_us-gaap_PreferredStockDividendRatePercentage_label_en-US" xlink:label="lab_us-gaap_PreferredStockDividendRatePercentage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred Stock, Dividend Rate, Percentage </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendRatePercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockDividendRatePercentage"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockDividendRatePercentage" xlink:to="lab_us-gaap_PreferredStockDividendRatePercentage" xlink:type="arc" order="1"/>

<link:label id="lab_good_TaylorPennsylvaniaIndustrialBuildingMember_5d108a37-f65f-4b1f-abf7-cd5d3378b2a3_terseLabel_en-US" xlink:label="lab_good_TaylorPennsylvaniaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Taylor, Pennsylvania Industrial Building </link:label>

<link:label id="lab_good_TaylorPennsylvaniaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_TaylorPennsylvaniaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Taylor, Pennsylvania Industrial Building [Member] </link:label>

<link:label id="lab_good_TaylorPennsylvaniaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_TaylorPennsylvaniaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Taylor, Pennsylvania Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_TaylorPennsylvaniaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_TaylorPennsylvaniaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_TaylorPennsylvaniaIndustrialBuildingMember" xlink:to="lab_good_TaylorPennsylvaniaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_469829dd-a896-4a44-9b63-bcec8e4844b1_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of credit facility, maximum borrowing capacity </link:label>

<link:label id="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of Credit Facility, Maximum Borrowing Capacity </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:to="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:type="arc" order="1"/>

<link:label id="lab_good_AtlantaGeorgiaIndustrialBuildingMember_d25ac46f-426d-4c6c-af76-80a4cc211dbf_terseLabel_en-US" xlink:label="lab_good_AtlantaGeorgiaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Atlanta, Georgia Industrial Building </link:label>

<link:label id="lab_good_AtlantaGeorgiaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_AtlantaGeorgiaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Atlanta, Georgia Industrial Building [Member] </link:label>

<link:label id="lab_good_AtlantaGeorgiaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_AtlantaGeorgiaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Atlanta, Georgia Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AtlantaGeorgiaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_AtlantaGeorgiaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AtlantaGeorgiaIndustrialBuildingMember" xlink:to="lab_good_AtlantaGeorgiaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberOfRealEstatePropertiesHeldForSale_cc04473e-907f-42c7-b5f7-002334d73edf_terseLabel_en-US" xlink:label="lab_good_NumberOfRealEstatePropertiesHeldForSale" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of real estate properties, held for sale </link:label>

<link:label id="lab_good_NumberOfRealEstatePropertiesHeldForSale_label_en-US" xlink:label="lab_good_NumberOfRealEstatePropertiesHeldForSale" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Real Estate Properties Held For Sale </link:label>

<link:label id="lab_good_NumberOfRealEstatePropertiesHeldForSale_documentation_en-US" xlink:label="lab_good_NumberOfRealEstatePropertiesHeldForSale" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of real estate properties held for sale. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberOfRealEstatePropertiesHeldForSale" xlink:href="good-20221231.xsd#good_NumberOfRealEstatePropertiesHeldForSale"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberOfRealEstatePropertiesHeldForSale" xlink:to="lab_good_NumberOfRealEstatePropertiesHeldForSale" xlink:type="arc" order="1"/>

<link:label id="lab_good_CrossvilleTennesseeIndustrialBuildingMember_cd0c441a-6a7d-4b02-ac3a-93533843dda5_terseLabel_en-US" xlink:label="lab_good_CrossvilleTennesseeIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Crossville, Tennessee Industrial Building </link:label>

<link:label id="lab_good_CrossvilleTennesseeIndustrialBuildingMember_label_en-US" xlink:label="lab_good_CrossvilleTennesseeIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Crossville, Tennessee Industrial Building [Member] </link:label>

<link:label id="lab_good_CrossvilleTennesseeIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_CrossvilleTennesseeIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Crossville, Tennessee Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CrossvilleTennesseeIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_CrossvilleTennesseeIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CrossvilleTennesseeIndustrialBuildingMember" xlink:to="lab_good_CrossvilleTennesseeIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberOfTrustSharesExchangedForLimitedPartnershipInterest_d4ad1633-ef54-4b31-afe2-3d563e8713bc_terseLabel_en-US" xlink:label="lab_good_NumberOfTrustSharesExchangedForLimitedPartnershipInterest" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of trust shares exchanged for limited partnership interest (in shares) </link:label>

<link:label id="lab_good_NumberOfTrustSharesExchangedForLimitedPartnershipInterest_label_en-US" xlink:label="lab_good_NumberOfTrustSharesExchangedForLimitedPartnershipInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Trust Shares Exchanged For Limited Partnership Interest </link:label>

<link:label id="lab_good_NumberOfTrustSharesExchangedForLimitedPartnershipInterest_documentation_en-US" xlink:label="lab_good_NumberOfTrustSharesExchangedForLimitedPartnershipInterest" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of trust shares exchanged for limited partnership interest. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberOfTrustSharesExchangedForLimitedPartnershipInterest" xlink:href="good-20221231.xsd#good_NumberOfTrustSharesExchangedForLimitedPartnershipInterest"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberOfTrustSharesExchangedForLimitedPartnershipInterest" xlink:to="lab_good_NumberOfTrustSharesExchangedForLimitedPartnershipInterest" xlink:type="arc" order="1"/>

<link:label id="lab_srt_RangeMember_c556907f-489c-48d3-bf1f-1509af90c62a_terseLabel_en-US" xlink:label="lab_srt_RangeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statistical Measurement [Domain] </link:label>

<link:label id="lab_srt_RangeMember_label_en-US" xlink:label="lab_srt_RangeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statistical Measurement [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RangeMember" xlink:to="lab_srt_RangeMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberOfLongTermMortgagesRepaid_8724fe92-4164-44b3-b081-72c01cfaf6d0_terseLabel_en-US" xlink:label="lab_good_NumberOfLongTermMortgagesRepaid" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of mortgages repaid </link:label>

<link:label id="lab_good_NumberOfLongTermMortgagesRepaid_label_en-US" xlink:label="lab_good_NumberOfLongTermMortgagesRepaid" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Long Term Mortgages Repaid </link:label>

<link:label id="lab_good_NumberOfLongTermMortgagesRepaid_documentation_en-US" xlink:label="lab_good_NumberOfLongTermMortgagesRepaid" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Long Term Mortgages Repaid </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberOfLongTermMortgagesRepaid" xlink:href="good-20221231.xsd#good_NumberOfLongTermMortgagesRepaid"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberOfLongTermMortgagesRepaid" xlink:to="lab_good_NumberOfLongTermMortgagesRepaid" xlink:type="arc" order="1"/>

<link:label id="lab_good_VariableRateTermLoanFacilityCMember_c39af604-ca7f-4d3f-8b2c-2b2aea0805b9_terseLabel_en-US" xlink:label="lab_good_VariableRateTermLoanFacilityCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate Term Loan Facility C </link:label>

<link:label id="lab_good_VariableRateTermLoanFacilityCMember_label_en-US" xlink:label="lab_good_VariableRateTermLoanFacilityCMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate Term Loan Facility C [Member] </link:label>

<link:label id="lab_good_VariableRateTermLoanFacilityCMember_documentation_en-US" xlink:label="lab_good_VariableRateTermLoanFacilityCMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate Term Loan Facility C </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_VariableRateTermLoanFacilityCMember" xlink:href="good-20221231.xsd#good_VariableRateTermLoanFacilityCMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_VariableRateTermLoanFacilityCMember" xlink:to="lab_good_VariableRateTermLoanFacilityCMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_PercentageReductionAtEachOfTheLeverageTiers_0126724f-9d1d-4e9d-9f67-525d351ee340_terseLabel_en-US" xlink:label="lab_good_PercentageReductionAtEachOfTheLeverageTiers" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reduction at each of the leverage tiers </link:label>

<link:label id="lab_good_PercentageReductionAtEachOfTheLeverageTiers_label_en-US" xlink:label="lab_good_PercentageReductionAtEachOfTheLeverageTiers" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage Reduction at Each of the Leverage Tiers </link:label>

<link:label id="lab_good_PercentageReductionAtEachOfTheLeverageTiers_documentation_en-US" xlink:label="lab_good_PercentageReductionAtEachOfTheLeverageTiers" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage Reduction at Each of the Leverage Tiers </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PercentageReductionAtEachOfTheLeverageTiers" xlink:href="good-20221231.xsd#good_PercentageReductionAtEachOfTheLeverageTiers"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PercentageReductionAtEachOfTheLeverageTiers" xlink:to="lab_good_PercentageReductionAtEachOfTheLeverageTiers" xlink:type="arc" order="1"/>

<link:label id="lab_good_TenantImprovementMember_add27090-f67a-43f8-8057-f1a7262e1408_terseLabel_en-US" xlink:label="lab_good_TenantImprovementMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tenant Improvements </link:label>

<link:label id="lab_good_TenantImprovementMember_label_en-US" xlink:label="lab_good_TenantImprovementMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tenant Improvement [Member] </link:label>

<link:label id="lab_good_TenantImprovementMember_documentation_en-US" xlink:label="lab_good_TenantImprovementMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tenant improvements. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_TenantImprovementMember" xlink:href="good-20221231.xsd#good_TenantImprovementMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_TenantImprovementMember" xlink:to="lab_good_TenantImprovementMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_ClintonvilleWisconsinIndustrialManufacturingBuildingMember_39a769a5-3b8c-4393-9992-e19cc664e63b_terseLabel_en-US" xlink:label="lab_good_ClintonvilleWisconsinIndustrialManufacturingBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Clintonville, Wisconsin Industrial Building </link:label>

<link:label id="lab_good_ClintonvilleWisconsinIndustrialManufacturingBuildingMember_label_en-US" xlink:label="lab_good_ClintonvilleWisconsinIndustrialManufacturingBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Clintonville Wisconsin Industrial Manufacturing Building [Member] </link:label>

<link:label id="lab_good_ClintonvilleWisconsinIndustrialManufacturingBuildingMember_documentation_en-US" xlink:label="lab_good_ClintonvilleWisconsinIndustrialManufacturingBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Clintonville Wisconsin industrial manufacturing building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ClintonvilleWisconsinIndustrialManufacturingBuildingMember" xlink:href="good-20221231.xsd#good_ClintonvilleWisconsinIndustrialManufacturingBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ClintonvilleWisconsinIndustrialManufacturingBuildingMember" xlink:to="lab_good_ClintonvilleWisconsinIndustrialManufacturingBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_FortLauderdaleFloridaOfficeBuildingMember_b7e80b4a-9414-4e95-8173-1075021ddb7b_terseLabel_en-US" xlink:label="lab_good_FortLauderdaleFloridaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fort Lauderdale, Florida Office Building </link:label>

<link:label id="lab_good_FortLauderdaleFloridaOfficeBuildingMember_label_en-US" xlink:label="lab_good_FortLauderdaleFloridaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fort Lauderdale, Florida Office Building [Member] </link:label>

<link:label id="lab_good_FortLauderdaleFloridaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_FortLauderdaleFloridaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fort Lauderdale, Florida Office Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_FortLauderdaleFloridaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_FortLauderdaleFloridaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_FortLauderdaleFloridaOfficeBuildingMember" xlink:to="lab_good_FortLauderdaleFloridaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_PinevilleNorthCarolinaIndustrialBuildingMember_b4786940-f551-42c0-813c-160d85bbcc7c_terseLabel_en-US" xlink:label="lab_good_PinevilleNorthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pineville, North Carolina Industrial Building </link:label>

<link:label id="lab_good_PinevilleNorthCarolinaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_PinevilleNorthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pineville North Carolina Industrial Building [Member] </link:label>

<link:label id="lab_good_PinevilleNorthCarolinaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_PinevilleNorthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pineville North Carolina industrial building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PinevilleNorthCarolinaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_PinevilleNorthCarolinaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PinevilleNorthCarolinaIndustrialBuildingMember" xlink:to="lab_good_PinevilleNorthCarolinaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_DelawareOhioIndustrialBuildingMember_b1168bc8-edda-4416-bf1b-80ee18c7319a_terseLabel_en-US" xlink:label="lab_good_DelawareOhioIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Delaware, Ohio Industrial Building </link:label>

<link:label id="lab_good_DelawareOhioIndustrialBuildingMember_label_en-US" xlink:label="lab_good_DelawareOhioIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Delaware, Ohio Industrial Building [Member] </link:label>

<link:label id="lab_good_DelawareOhioIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_DelawareOhioIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Delaware, Ohio Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DelawareOhioIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_DelawareOhioIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DelawareOhioIndustrialBuildingMember" xlink:to="lab_good_DelawareOhioIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NetIncomeLoss_357f2e7c-3e67-4f79-8b53-070f119d3fbe_totalLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net income attributable to the Company </link:label>

<link:label id="lab_us-gaap_NetIncomeLoss_label_en-US" xlink:label="lab_us-gaap_NetIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Income (Loss) Attributable to Parent </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLoss"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetIncomeLoss" xlink:to="lab_us-gaap_NetIncomeLoss" xlink:type="arc" order="1"/>

<link:label id="lab_good_ScheduleOfIntangibleAssetsLiabilitiesAndAccumulatedAmortizationTableTableTextBlock_f688740c-f300-4765-8635-e38660f99c77_terseLabel_en-US" xlink:label="lab_good_ScheduleOfIntangibleAssetsLiabilitiesAndAccumulatedAmortizationTableTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Carrying Value of Intangible Assets and Accumulated Amortization </link:label>

<link:label id="lab_good_ScheduleOfIntangibleAssetsLiabilitiesAndAccumulatedAmortizationTableTableTextBlock_label_en-US" xlink:label="lab_good_ScheduleOfIntangibleAssetsLiabilitiesAndAccumulatedAmortizationTableTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Intangible Assets Liabilities And Accumulated Amortization Table [Table Text Block] </link:label>

<link:label id="lab_good_ScheduleOfIntangibleAssetsLiabilitiesAndAccumulatedAmortizationTableTableTextBlock_documentation_en-US" xlink:label="lab_good_ScheduleOfIntangibleAssetsLiabilitiesAndAccumulatedAmortizationTableTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of intangible assets, liabilities and accumulated amortization. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ScheduleOfIntangibleAssetsLiabilitiesAndAccumulatedAmortizationTableTableTextBlock" xlink:href="good-20221231.xsd#good_ScheduleOfIntangibleAssetsLiabilitiesAndAccumulatedAmortizationTableTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ScheduleOfIntangibleAssetsLiabilitiesAndAccumulatedAmortizationTableTableTextBlock" xlink:to="lab_good_ScheduleOfIntangibleAssetsLiabilitiesAndAccumulatedAmortizationTableTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock_fac38b65-d945-4776-8030-0e6e832283f7_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Principal Payments of Mortgage Notes Payable </link:label>

<link:label id="lab_us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Maturities of Long-Term Debt [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SubsequentEventTypeAxis_3f5551fc-d496-4b60-bd46-7ed5b5fe65b3_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsequent Event Type [Axis] </link:label>

<link:label id="lab_us-gaap_SubsequentEventTypeAxis_label_en-US" xlink:label="lab_us-gaap_SubsequentEventTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsequent Event Type [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventTypeAxis" xlink:to="lab_us-gaap_SubsequentEventTypeAxis" xlink:type="arc" order="1"/>

<link:label id="lab_good_RaleighNorthCarolinaIndustrialBuildingMember_716de106-17bd-4dae-baaa-c85e535847af_terseLabel_en-US" xlink:label="lab_good_RaleighNorthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Raleigh, North Carolina Industrial Building </link:label>

<link:label id="lab_good_RaleighNorthCarolinaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_RaleighNorthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Raleigh North Carolina Industrial Building [Member] </link:label>

<link:label id="lab_good_RaleighNorthCarolinaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_RaleighNorthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Raleigh North Carolina industrial building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_RaleighNorthCarolinaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_RaleighNorthCarolinaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_RaleighNorthCarolinaIndustrialBuildingMember" xlink:to="lab_good_RaleighNorthCarolinaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_OcalaFloridaIndustrialBuildingMember_950eec60-7329-4b52-b69e-11909fbca505_terseLabel_en-US" xlink:label="lab_good_OcalaFloridaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ocala, Florida Industrial Building </link:label>

<link:label id="lab_good_OcalaFloridaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_OcalaFloridaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ocala, Florida Industrial Building [Member] </link:label>

<link:label id="lab_good_OcalaFloridaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_OcalaFloridaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ocala, Florida Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_OcalaFloridaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_OcalaFloridaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_OcalaFloridaIndustrialBuildingMember" xlink:to="lab_good_OcalaFloridaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_JacksonTennesseeIndustrialBuildingMember_bd5be9b5-5fa5-4954-8d1a-1451e52b2071_terseLabel_en-US" xlink:label="lab_good_JacksonTennesseeIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Jackson, Tennessee Industrial Building </link:label>

<link:label id="lab_good_JacksonTennesseeIndustrialBuildingMember_label_en-US" xlink:label="lab_good_JacksonTennesseeIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Jackson, Tennessee Industrial Building [Member] </link:label>

<link:label id="lab_good_JacksonTennesseeIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_JacksonTennesseeIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Jackson, Tennessee Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_JacksonTennesseeIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_JacksonTennesseeIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_JacksonTennesseeIndustrialBuildingMember" xlink:to="lab_good_JacksonTennesseeIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_IncomeLossFromRealEstateAndRelatedAssetsHeldForSale_fee1a2ff-7fae-4929-a570-216aea4f56b3_totalLabel_en-US" xlink:label="lab_good_IncomeLossFromRealEstateAndRelatedAssetsHeldForSale" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income from real estate and related assets sold </link:label>

<link:label id="lab_good_IncomeLossFromRealEstateAndRelatedAssetsHeldForSale_label_en-US" xlink:label="lab_good_IncomeLossFromRealEstateAndRelatedAssetsHeldForSale" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Loss From Real Estate And Related Assets Held For Sale </link:label>

<link:label id="lab_good_IncomeLossFromRealEstateAndRelatedAssetsHeldForSale_documentation_en-US" xlink:label="lab_good_IncomeLossFromRealEstateAndRelatedAssetsHeldForSale" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income loss from real estate and related assets held for sale. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_IncomeLossFromRealEstateAndRelatedAssetsHeldForSale" xlink:href="good-20221231.xsd#good_IncomeLossFromRealEstateAndRelatedAssetsHeldForSale"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_IncomeLossFromRealEstateAndRelatedAssetsHeldForSale" xlink:to="lab_good_IncomeLossFromRealEstateAndRelatedAssetsHeldForSale" xlink:type="arc" order="1"/>

<link:label id="lab_good_AdministrationFee_3f8b37ff-4785-4171-a4f7-7c754aa7e820_verboseLabel_en-US" xlink:label="lab_good_AdministrationFee" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Administration fee </link:label>

<link:label id="lab_good_AdministrationFee_label_en-US" xlink:label="lab_good_AdministrationFee" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Administration Fee </link:label>

<link:label id="lab_good_AdministrationFee_documentation_en-US" xlink:label="lab_good_AdministrationFee" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Administration fee. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AdministrationFee" xlink:href="good-20221231.xsd#good_AdministrationFee"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AdministrationFee" xlink:to="lab_good_AdministrationFee" xlink:type="arc" order="1"/>

<link:label id="lab_good_ReturnOfCapitalMember_fc961913-a0ad-4be1-bf5d-1eccceef16ab_terseLabel_en-US" xlink:label="lab_good_ReturnOfCapitalMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Return of Capital </link:label>

<link:label id="lab_good_ReturnOfCapitalMember_label_en-US" xlink:label="lab_good_ReturnOfCapitalMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Return Of Capital [Member] </link:label>

<link:label id="lab_good_ReturnOfCapitalMember_documentation_en-US" xlink:label="lab_good_ReturnOfCapitalMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Return of capital. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ReturnOfCapitalMember" xlink:href="good-20221231.xsd#good_ReturnOfCapitalMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ReturnOfCapitalMember" xlink:to="lab_good_ReturnOfCapitalMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DerivativeInstrumentRiskAxis_0fa93795-ca2c-45e4-bf45-5ee15f28ed92_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeInstrumentRiskAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Instrument [Axis] </link:label>

<link:label id="lab_us-gaap_DerivativeInstrumentRiskAxis_label_en-US" xlink:label="lab_us-gaap_DerivativeInstrumentRiskAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Instrument [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis" xlink:to="lab_us-gaap_DerivativeInstrumentRiskAxis" xlink:type="arc" order="1"/>

<link:label id="lab_good_TemporaryEquityContractTermsMinimumVoteNeededtoTriggerChangeinControlFromTenderOffer_bdd5ab7d-f515-4195-923d-296d535aba8f_terseLabel_en-US" xlink:label="lab_good_TemporaryEquityContractTermsMinimumVoteNeededtoTriggerChangeinControlFromTenderOffer" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Minimum vote need to trigger change in control from tender offer </link:label>

<link:label id="lab_good_TemporaryEquityContractTermsMinimumVoteNeededtoTriggerChangeinControlFromTenderOffer_label_en-US" xlink:label="lab_good_TemporaryEquityContractTermsMinimumVoteNeededtoTriggerChangeinControlFromTenderOffer" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Temporary Equity, Contract Terms, Minimum Vote Needed to Trigger Change in Control From Tender Offer </link:label>

<link:label id="lab_good_TemporaryEquityContractTermsMinimumVoteNeededtoTriggerChangeinControlFromTenderOffer_documentation_en-US" xlink:label="lab_good_TemporaryEquityContractTermsMinimumVoteNeededtoTriggerChangeinControlFromTenderOffer" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Temporary Equity, Contract Terms, Minimum Vote Needed to Trigger Change in Control From Tender Offer </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_TemporaryEquityContractTermsMinimumVoteNeededtoTriggerChangeinControlFromTenderOffer" xlink:href="good-20221231.xsd#good_TemporaryEquityContractTermsMinimumVoteNeededtoTriggerChangeinControlFromTenderOffer"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_TemporaryEquityContractTermsMinimumVoteNeededtoTriggerChangeinControlFromTenderOffer" xlink:to="lab_good_TemporaryEquityContractTermsMinimumVoteNeededtoTriggerChangeinControlFromTenderOffer" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NumberOfOperatingSegments_a69cacae-28d0-47d0-9a14-3c0eac83c907_terseLabel_en-US" xlink:label="lab_us-gaap_NumberOfOperatingSegments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of operating segments </link:label>

<link:label id="lab_us-gaap_NumberOfOperatingSegments_label_en-US" xlink:label="lab_us-gaap_NumberOfOperatingSegments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Operating Segments </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NumberOfOperatingSegments"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NumberOfOperatingSegments" xlink:to="lab_us-gaap_NumberOfOperatingSegments" xlink:type="arc" order="1"/>

<link:label id="lab_good_DeferredRentReceivablesWriteoffs_40c5ae71-8d0a-48ba-9121-3ce58df84169_verboseLabel_en-US" xlink:label="lab_good_DeferredRentReceivablesWriteoffs" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred rent write-offs </link:label>

<link:label id="lab_good_DeferredRentReceivablesWriteoffs_label_en-US" xlink:label="lab_good_DeferredRentReceivablesWriteoffs" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Rent Receivables, Write-offs </link:label>

<link:label id="lab_good_DeferredRentReceivablesWriteoffs_documentation_en-US" xlink:label="lab_good_DeferredRentReceivablesWriteoffs" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Rent Receivables, Write-offs </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DeferredRentReceivablesWriteoffs" xlink:href="good-20221231.xsd#good_DeferredRentReceivablesWriteoffs"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DeferredRentReceivablesWriteoffs" xlink:to="lab_good_DeferredRentReceivablesWriteoffs" xlink:type="arc" order="1"/>

<link:label id="lab_good_MtPoconoPennsylvaniaCommercialAndManufacturingBuildingMember_4b3dc85b-4991-457b-b3f4-06df423d39fa_terseLabel_en-US" xlink:label="lab_good_MtPoconoPennsylvaniaCommercialAndManufacturingBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Mt. Pocono, Pennsylvania Industrial Building </link:label>

<link:label id="lab_good_MtPoconoPennsylvaniaCommercialAndManufacturingBuildingMember_label_en-US" xlink:label="lab_good_MtPoconoPennsylvaniaCommercialAndManufacturingBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Mt Pocono Pennsylvania Commercial And Manufacturing Building [Member] </link:label>

<link:label id="lab_good_MtPoconoPennsylvaniaCommercialAndManufacturingBuildingMember_documentation_en-US" xlink:label="lab_good_MtPoconoPennsylvaniaCommercialAndManufacturingBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Mt. Pocono Pennsylvania commercial and manufacturing building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_MtPoconoPennsylvaniaCommercialAndManufacturingBuildingMember" xlink:href="good-20221231.xsd#good_MtPoconoPennsylvaniaCommercialAndManufacturingBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_MtPoconoPennsylvaniaCommercialAndManufacturingBuildingMember" xlink:to="lab_good_MtPoconoPennsylvaniaCommercialAndManufacturingBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StatementOfCashFlowsAbstract_3b6ef823-1452-461e-8d33-daf4b5447ea8_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfCashFlowsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement of Cash Flows [Abstract] </link:label>

<link:label id="lab_us-gaap_StatementOfCashFlowsAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfCashFlowsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement of Cash Flows [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfCashFlowsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementOfCashFlowsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementOfCashFlowsAbstract" xlink:to="lab_us-gaap_StatementOfCashFlowsAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateCostOfRealEstateSold_c8c7a808-66a3-4e0a-a1f9-f0da65c4d638_negatedLabel_en-US" xlink:label="lab_us-gaap_RealEstateCostOfRealEstateSold" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dispositions during period </link:label>

<link:label id="lab_us-gaap_RealEstateCostOfRealEstateSold_label_en-US" xlink:label="lab_us-gaap_RealEstateCostOfRealEstateSold" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Cost of Investment in Real Estate Sold </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateCostOfRealEstateSold" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateCostOfRealEstateSold"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateCostOfRealEstateSold" xlink:to="lab_us-gaap_RealEstateCostOfRealEstateSold" xlink:type="arc" order="1"/>

<link:label id="lab_good_PreferredStockWriteOffOfOfferingCosts_f7c2f8b4-849b-4af6-95ad-48a652a17db2_negatedTerseLabel_en-US" xlink:label="lab_good_PreferredStockWriteOffOfOfferingCosts" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series D preferred stock offering costs write off </link:label>

<link:label id="lab_good_PreferredStockWriteOffOfOfferingCosts_63ec38dc-ee5a-4467-85e7-7ce1e36cca3f_terseLabel_en-US" xlink:label="lab_good_PreferredStockWriteOffOfOfferingCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series D Preferred Stock offering cost write off </link:label>

<link:label id="lab_good_PreferredStockWriteOffOfOfferingCosts_label_en-US" xlink:label="lab_good_PreferredStockWriteOffOfOfferingCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred Stock, Write Off Of Offering Costs </link:label>

<link:label id="lab_good_PreferredStockWriteOffOfOfferingCosts_documentation_en-US" xlink:label="lab_good_PreferredStockWriteOffOfOfferingCosts" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred Stock, Write Off Of Offering Costs </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PreferredStockWriteOffOfOfferingCosts" xlink:href="good-20221231.xsd#good_PreferredStockWriteOffOfOfferingCosts"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PreferredStockWriteOffOfOfferingCosts" xlink:to="lab_good_PreferredStockWriteOffOfOfferingCosts" xlink:type="arc" order="1"/>

<link:label id="lab_good_StCharlesMissouriIndustrialBuildingMember_5ad8ed7f-fa13-4e3d-a555-6c0ea8049974_terseLabel_en-US" xlink:label="lab_good_StCharlesMissouriIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> St. Charles, Missouri Industrial Building </link:label>

<link:label id="lab_good_StCharlesMissouriIndustrialBuildingMember_label_en-US" xlink:label="lab_good_StCharlesMissouriIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> St. Charles, Missouri Industrial Building [Member] </link:label>

<link:label id="lab_good_StCharlesMissouriIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_StCharlesMissouriIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> St. Charles, Missouri Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_StCharlesMissouriIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_StCharlesMissouriIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_StCharlesMissouriIndustrialBuildingMember" xlink:to="lab_good_StCharlesMissouriIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_ClevelandOhioIndustrialBuildingMember_e91f700f-d8a0-4fe6-a931-392fa4d7c054_terseLabel_en-US" xlink:label="lab_good_ClevelandOhioIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cleveland, Ohio Industrial Building </link:label>

<link:label id="lab_good_ClevelandOhioIndustrialBuildingMember_label_en-US" xlink:label="lab_good_ClevelandOhioIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cleveland, Ohio Industrial Building [Member] </link:label>

<link:label id="lab_good_ClevelandOhioIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_ClevelandOhioIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cleveland, Ohio Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ClevelandOhioIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_ClevelandOhioIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ClevelandOhioIndustrialBuildingMember" xlink:to="lab_good_ClevelandOhioIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_c167d149-2dd9-4072-a90b-21246d6ebf78_totalLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net cash provided by operating activities </link:label>

<link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Cash Provided by (Used in) Operating Activities </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DerivativeAssets_3a9408aa-d5d1-472e-977a-4121fb5897e3_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative asset </link:label>

<link:label id="lab_us-gaap_DerivativeAssets_label_en-US" xlink:label="lab_us-gaap_DerivativeAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Asset </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeAssets"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeAssets" xlink:to="lab_us-gaap_DerivativeAssets" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RelatedPartyTransactionDomain_8c620905-21f0-41eb-b8c2-00dcecf2de58_terseLabel_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Related Party Transaction [Domain] </link:label>

<link:label id="lab_us-gaap_RelatedPartyTransactionDomain_label_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Related Party Transaction [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain" xlink:to="lab_us-gaap_RelatedPartyTransactionDomain" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OtherLiabilities_f24d03d0-2557-47ec-aa1e-1e7dde3fefd8_terseLabel_en-US" xlink:label="lab_us-gaap_OtherLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other liabilities </link:label>

<link:label id="lab_us-gaap_OtherLiabilities_label_en-US" xlink:label="lab_us-gaap_OtherLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Liabilities </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherLiabilities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherLiabilities" xlink:to="lab_us-gaap_OtherLiabilities" xlink:type="arc" order="1"/>

<link:label id="lab_good_KingofPrussiaPennsylvaniaOfficeBuildingMember_accf6dd6-8edc-40d5-b805-4885a5904518_terseLabel_en-US" xlink:label="lab_good_KingofPrussiaPennsylvaniaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> King of Prussia, Pennsylvania Office Building </link:label>

<link:label id="lab_good_KingofPrussiaPennsylvaniaOfficeBuildingMember_label_en-US" xlink:label="lab_good_KingofPrussiaPennsylvaniaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> King of Prussia, Pennsylvania Office Building [Member] </link:label>

<link:label id="lab_good_KingofPrussiaPennsylvaniaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_KingofPrussiaPennsylvaniaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> King of Prussia, Pennsylvania Office Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_KingofPrussiaPennsylvaniaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_KingofPrussiaPennsylvaniaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_KingofPrussiaPennsylvaniaOfficeBuildingMember" xlink:to="lab_good_KingofPrussiaPennsylvaniaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_UnconditionalVoluntaryAndIrrevocableWaivers_178436c6-0152-43d9-be57-f6159b00d7d1_terseLabel_en-US" xlink:label="lab_good_UnconditionalVoluntaryAndIrrevocableWaivers" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unconditional voluntary and irrevocable waivers </link:label>

<link:label id="lab_good_UnconditionalVoluntaryAndIrrevocableWaivers_label_en-US" xlink:label="lab_good_UnconditionalVoluntaryAndIrrevocableWaivers" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unconditional Voluntary And Irrevocable Waivers </link:label>

<link:label id="lab_good_UnconditionalVoluntaryAndIrrevocableWaivers_documentation_en-US" xlink:label="lab_good_UnconditionalVoluntaryAndIrrevocableWaivers" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Credit For Unconditional Voluntary And Irrevocable Waivers </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_UnconditionalVoluntaryAndIrrevocableWaivers" xlink:href="good-20221231.xsd#good_UnconditionalVoluntaryAndIrrevocableWaivers"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_UnconditionalVoluntaryAndIrrevocableWaivers" xlink:to="lab_good_UnconditionalVoluntaryAndIrrevocableWaivers" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AdvanceRent_e0edd2f3-1801-418b-aa10-21645130688b_terseLabel_en-US" xlink:label="lab_us-gaap_AdvanceRent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Prepaid rent </link:label>

<link:label id="lab_us-gaap_AdvanceRent_label_en-US" xlink:label="lab_us-gaap_AdvanceRent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Advance Rent </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdvanceRent" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdvanceRent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AdvanceRent" xlink:to="lab_us-gaap_AdvanceRent" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AccumulatedDistributionsInExcessOfNetIncome_48b74c16-1ba3-414d-af83-c9ea8dd0973d_negatedLabel_en-US" xlink:label="lab_us-gaap_AccumulatedDistributionsInExcessOfNetIncome" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Distributions in excess of accumulated earnings </link:label>

<link:label id="lab_us-gaap_AccumulatedDistributionsInExcessOfNetIncome_label_en-US" xlink:label="lab_us-gaap_AccumulatedDistributionsInExcessOfNetIncome" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accumulated Distributions in Excess of Net Income </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDistributionsInExcessOfNetIncome" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedDistributionsInExcessOfNetIncome"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccumulatedDistributionsInExcessOfNetIncome" xlink:to="lab_us-gaap_AccumulatedDistributionsInExcessOfNetIncome" xlink:type="arc" order="1"/>

<link:label id="lab_good_EatontownNewJerseyOfficeBuildingMember_1f4c4aae-30bd-4067-8095-215243638f54_terseLabel_en-US" xlink:label="lab_good_EatontownNewJerseyOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Eatontown, New Jersey Office Building </link:label>

<link:label id="lab_good_EatontownNewJerseyOfficeBuildingMember_label_en-US" xlink:label="lab_good_EatontownNewJerseyOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Eatontown New Jersey Office Building [Member] </link:label>

<link:label id="lab_good_EatontownNewJerseyOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_EatontownNewJerseyOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Eatontown New Jersey office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_EatontownNewJerseyOfficeBuildingMember" xlink:href="good-20221231.xsd#good_EatontownNewJerseyOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_EatontownNewJerseyOfficeBuildingMember" xlink:to="lab_good_EatontownNewJerseyOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_DocumentAnnualReport_66aea419-ea13-4fe6-bea0-01abec7469ac_terseLabel_en-US" xlink:label="lab_dei_DocumentAnnualReport" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Annual Report </link:label>

<link:label id="lab_dei_DocumentAnnualReport_label_en-US" xlink:label="lab_dei_DocumentAnnualReport" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Annual Report </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentAnnualReport" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentAnnualReport"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentAnnualReport" xlink:to="lab_dei_DocumentAnnualReport" xlink:type="arc" order="1"/>

<link:label id="lab_good_AdjustmentstoAdditionalPaidinCapitalAdjustmenttoOperatingPartnershipOwnership_6257ebea-7227-4f47-8ad7-4a9d044c9373_terseLabel_en-US" xlink:label="lab_good_AdjustmentstoAdditionalPaidinCapitalAdjustmenttoOperatingPartnershipOwnership" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Adjustment to OP Units held by Non-controlling OP Unitholders resulting from changes in ownership of the Operating Partnership </link:label>

<link:label id="lab_good_AdjustmentstoAdditionalPaidinCapitalAdjustmenttoOperatingPartnershipOwnership_label_en-US" xlink:label="lab_good_AdjustmentstoAdditionalPaidinCapitalAdjustmenttoOperatingPartnershipOwnership" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Adjustments to Additional Paid in Capital, Adjustment to Operating Partnership Ownership </link:label>

<link:label id="lab_good_AdjustmentstoAdditionalPaidinCapitalAdjustmenttoOperatingPartnershipOwnership_documentation_en-US" xlink:label="lab_good_AdjustmentstoAdditionalPaidinCapitalAdjustmenttoOperatingPartnershipOwnership" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Adjustments to Additional Paid in Capital, Adjustment to Operating Partnership Ownership </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AdjustmentstoAdditionalPaidinCapitalAdjustmenttoOperatingPartnershipOwnership" xlink:href="good-20221231.xsd#good_AdjustmentstoAdditionalPaidinCapitalAdjustmenttoOperatingPartnershipOwnership"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AdjustmentstoAdditionalPaidinCapitalAdjustmenttoOperatingPartnershipOwnership" xlink:to="lab_good_AdjustmentstoAdditionalPaidinCapitalAdjustmenttoOperatingPartnershipOwnership" xlink:type="arc" order="1"/>

<link:label id="lab_srt_SubsidiariesMember_b6e76f59-a920-4066-bf77-db9e42f72d17_terseLabel_en-US" xlink:label="lab_srt_SubsidiariesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> GCLP Business Trust I </link:label>

<link:label id="lab_srt_SubsidiariesMember_label_en-US" xlink:label="lab_srt_SubsidiariesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsidiaries [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_SubsidiariesMember" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_SubsidiariesMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_SubsidiariesMember" xlink:to="lab_srt_SubsidiariesMember" xlink:type="arc" order="1"/>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationLineItems_0663ce56-abb2-43c4-9ec1-e5019b7c44c8_terseLabel_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] </link:label>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationLineItems_label_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationLineItems" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RealEstateAndAccumulatedDepreciationLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationLineItems" xlink:to="lab_srt_RealEstateAndAccumulatedDepreciationLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_srt_StatementGeographicalAxis_47c1e9d6-b0d7-4724-b0bb-beab67f9424f_terseLabel_en-US" xlink:label="lab_srt_StatementGeographicalAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Geographical [Axis] </link:label>

<link:label id="lab_srt_StatementGeographicalAxis_label_en-US" xlink:label="lab_srt_StatementGeographicalAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Geographical [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_StatementGeographicalAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_StatementGeographicalAxis" xlink:to="lab_srt_StatementGeographicalAxis" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StockIssuedDuringPeriodValueNewIssues_acb1321c-d24b-429b-a7ca-97a3a1609af6_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Issuance of Series A, B and F preferred stock and common stock, net </link:label>

<link:label id="lab_us-gaap_StockIssuedDuringPeriodValueNewIssues_label_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Issued During Period, Value, New Issues </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:to="lab_us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:type="arc" order="1"/>

<link:label id="lab_good_ColleyvilleTexasRetailBuildingMember_06926fbd-0c7d-4e35-b1e7-d2c5e5b40444_terseLabel_en-US" xlink:label="lab_good_ColleyvilleTexasRetailBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Colleyville, Texas Retail Building </link:label>

<link:label id="lab_good_ColleyvilleTexasRetailBuildingMember_label_en-US" xlink:label="lab_good_ColleyvilleTexasRetailBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Colleyville Texas Retail Building [Member] </link:label>

<link:label id="lab_good_ColleyvilleTexasRetailBuildingMember_documentation_en-US" xlink:label="lab_good_ColleyvilleTexasRetailBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Colleyville Texas Retail Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ColleyvilleTexasRetailBuildingMember" xlink:href="good-20221231.xsd#good_ColleyvilleTexasRetailBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ColleyvilleTexasRetailBuildingMember" xlink:to="lab_good_ColleyvilleTexasRetailBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_MoorestownNewJerseyIndustrialBuildingMember_b0d6244d-8ffb-4a12-98f0-6b0d61f10aa3_terseLabel_en-US" xlink:label="lab_good_MoorestownNewJerseyIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Moorestown, New Jersey Industrial Building </link:label>

<link:label id="lab_good_MoorestownNewJerseyIndustrialBuildingMember_label_en-US" xlink:label="lab_good_MoorestownNewJerseyIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Moorestown, New Jersey Industrial Building [Member] </link:label>

<link:label id="lab_good_MoorestownNewJerseyIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_MoorestownNewJerseyIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Moorestown, New Jersey Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_MoorestownNewJerseyIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_MoorestownNewJerseyIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_MoorestownNewJerseyIndustrialBuildingMember" xlink:to="lab_good_MoorestownNewJerseyIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DebtDisclosureTextBlock_71eadba1-b74d-43d5-8f3d-75bb50a65b3c_terseLabel_en-US" xlink:label="lab_us-gaap_DebtDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Mortgage Notes Payable and Credit Facility </link:label>

<link:label id="lab_us-gaap_DebtDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_DebtDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Disclosure [Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtDisclosureTextBlock" xlink:to="lab_us-gaap_DebtDisclosureTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateInvestmentPropertyNet_7692f488-79a6-47da-ab13-461db6f839ae_totalLabel_en-US" xlink:label="lab_us-gaap_RealEstateInvestmentPropertyNet" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total real estate, net </link:label>

<link:label id="lab_us-gaap_RealEstateInvestmentPropertyNet_label_en-US" xlink:label="lab_us-gaap_RealEstateInvestmentPropertyNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Investment Property, Net </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateInvestmentPropertyNet" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateInvestmentPropertyNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateInvestmentPropertyNet" xlink:to="lab_us-gaap_RealEstateInvestmentPropertyNet" xlink:type="arc" order="1"/>

<link:label id="lab_good_FortPayneAlabamaIndustrialBuildingMember_349a1927-ab07-4ae8-8f53-95d175a934e2_terseLabel_en-US" xlink:label="lab_good_FortPayneAlabamaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fort Payne, Alabama Industrial Building </link:label>

<link:label id="lab_good_FortPayneAlabamaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_FortPayneAlabamaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fort Payne, Alabama Industrial Building [Member] </link:label>

<link:label id="lab_good_FortPayneAlabamaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_FortPayneAlabamaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fort Payne, Alabama Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_FortPayneAlabamaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_FortPayneAlabamaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_FortPayneAlabamaIndustrialBuildingMember" xlink:to="lab_good_FortPayneAlabamaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_AboveAndBelowMarketLeasesMember_87d54f9a-0b35-4da4-b2c6-4d067591a914_terseLabel_en-US" xlink:label="lab_good_AboveAndBelowMarketLeasesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Above and Below Market Leases </link:label>

<link:label id="lab_good_AboveAndBelowMarketLeasesMember_label_en-US" xlink:label="lab_good_AboveAndBelowMarketLeasesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Above And Below Market Leases [Member] </link:label>

<link:label id="lab_good_AboveAndBelowMarketLeasesMember_documentation_en-US" xlink:label="lab_good_AboveAndBelowMarketLeasesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Above And Below Market Leases [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AboveAndBelowMarketLeasesMember" xlink:href="good-20221231.xsd#good_AboveAndBelowMarketLeasesMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AboveAndBelowMarketLeasesMember" xlink:to="lab_good_AboveAndBelowMarketLeasesMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityShellCompany_d0ccb490-b3e2-4954-95c9-21fdc8ae31b8_terseLabel_en-US" xlink:label="lab_dei_EntityShellCompany" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Shell Company </link:label>

<link:label id="lab_dei_EntityShellCompany_label_en-US" xlink:label="lab_dei_EntityShellCompany" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Shell Company </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityShellCompany"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityShellCompany" xlink:to="lab_dei_EntityShellCompany" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_a7a3afa2-3477-446e-bceb-e92511218347_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2023 </link:label>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, to be Paid, Year One </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:type="arc" order="1"/>

<link:label id="lab_good_BaytownTexasOfficeBuildingMember_4e6ffdde-43bd-42c4-89f7-0106836b56c3_terseLabel_en-US" xlink:label="lab_good_BaytownTexasOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Baytown, Texas Medical Office Building </link:label>

<link:label id="lab_good_BaytownTexasOfficeBuildingMember_label_en-US" xlink:label="lab_good_BaytownTexasOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Baytown Texas Office Building [Member] </link:label>

<link:label id="lab_good_BaytownTexasOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_BaytownTexasOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Baytown Texas office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BaytownTexasOfficeBuildingMember" xlink:href="good-20221231.xsd#good_BaytownTexasOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BaytownTexasOfficeBuildingMember" xlink:to="lab_good_BaytownTexasOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_InterestRateFairValueHedgeDerivativeAtFairValueNet_70e9ddec-41d8-415b-b259-e3c6a70c7727_terseLabel_en-US" xlink:label="lab_us-gaap_InterestRateFairValueHedgeDerivativeAtFairValueNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate Fair Value </link:label>

<link:label id="lab_us-gaap_InterestRateFairValueHedgeDerivativeAtFairValueNet_label_en-US" xlink:label="lab_us-gaap_InterestRateFairValueHedgeDerivativeAtFairValueNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest Rate Fair Value Hedge Derivative at Fair Value, Net </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateFairValueHedgeDerivativeAtFairValueNet" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateFairValueHedgeDerivativeAtFairValueNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestRateFairValueHedgeDerivativeAtFairValueNet" xlink:to="lab_us-gaap_InterestRateFairValueHedgeDerivativeAtFairValueNet" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_26a133dc-4058-4b17-94dc-c748a8d518a4_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2025 </link:label>

<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Maturity, Year Three </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:type="arc" order="1"/>

<link:label id="lab_good_TempleTexasIndustrialBuildingMember_0fe85884-9d02-4c47-9786-e833c6a54444_terseLabel_en-US" xlink:label="lab_good_TempleTexasIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Temple, Texas Industrial Building </link:label>

<link:label id="lab_good_TempleTexasIndustrialBuildingMember_label_en-US" xlink:label="lab_good_TempleTexasIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Temple, Texas Industrial Building [Member] </link:label>

<link:label id="lab_good_TempleTexasIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_TempleTexasIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Temple, Texas Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_TempleTexasIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_TempleTexasIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_TempleTexasIndustrialBuildingMember" xlink:to="lab_good_TempleTexasIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SubsequentEventMember_457fff6a-2740-489b-b4a5-0c86395b5edd_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsequent Event </link:label>

<link:label id="lab_us-gaap_SubsequentEventMember_label_en-US" xlink:label="lab_us-gaap_SubsequentEventMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsequent Event [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventMember" xlink:to="lab_us-gaap_SubsequentEventMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_DocumentPeriodEndDate_5d201c2c-2e2e-485b-9b7e-afa881385116_terseLabel_en-US" xlink:label="lab_dei_DocumentPeriodEndDate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Period End Date </link:label>

<link:label id="lab_dei_DocumentPeriodEndDate_label_en-US" xlink:label="lab_dei_DocumentPeriodEndDate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Period End Date </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentPeriodEndDate"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentPeriodEndDate" xlink:to="lab_dei_DocumentPeriodEndDate" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears_9bc74fb6-dbf4-4135-bd7a-eb4862ce12cc_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2027 </link:label>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessor, Operating Lease, Payment to be Received, Year Five </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_Assets_d775a6aa-e3a9-43f7-8b72-75dde37d690f_totalLabel_en-US" xlink:label="lab_us-gaap_Assets" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> TOTAL ASSETS </link:label>

<link:label id="lab_us-gaap_Assets_label_en-US" xlink:label="lab_us-gaap_Assets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Assets </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Assets"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Assets" xlink:to="lab_us-gaap_Assets" xlink:type="arc" order="1"/>

<link:label id="lab_good_FixedAssetAdditionsPaidForByTenant_5aa386ed-3698-4f6f-ae21-41fb5566d113_terseLabel_en-US" xlink:label="lab_good_FixedAssetAdditionsPaidForByTenant" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tenant funded fixed asset improvements included in deferred rent liability, net </link:label>

<link:label id="lab_good_FixedAssetAdditionsPaidForByTenant_label_en-US" xlink:label="lab_good_FixedAssetAdditionsPaidForByTenant" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fixed Asset Additions Paid For By Tenant </link:label>

<link:label id="lab_good_FixedAssetAdditionsPaidForByTenant_documentation_en-US" xlink:label="lab_good_FixedAssetAdditionsPaidForByTenant" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fixed asset additions paid for by tenant. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_FixedAssetAdditionsPaidForByTenant" xlink:href="good-20221231.xsd#good_FixedAssetAdditionsPaidForByTenant"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_FixedAssetAdditionsPaidForByTenant" xlink:to="lab_good_FixedAssetAdditionsPaidForByTenant" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_EarningsPerShareAbstract_4f0e6e90-2b3c-460d-88e6-9532b884c83f_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> (Loss) income per weighted average share of common stock - basic & diluted </link:label>

<link:label id="lab_us-gaap_EarningsPerShareAbstract_label_en-US" xlink:label="lab_us-gaap_EarningsPerShareAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings Per Share [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerShareAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerShareAbstract" xlink:to="lab_us-gaap_EarningsPerShareAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_VillaRicaGeorgiaIndustrialBuildingMember_023a0a2b-dfb5-43ef-8072-c44d6195afc9_terseLabel_en-US" xlink:label="lab_good_VillaRicaGeorgiaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Villa Rica, Georgia Industrial Building </link:label>

<link:label id="lab_good_VillaRicaGeorgiaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_VillaRicaGeorgiaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Villa Rica Georgia Industrial Building [Member] </link:label>

<link:label id="lab_good_VillaRicaGeorgiaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_VillaRicaGeorgiaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Villa Rica, Georgia Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_VillaRicaGeorgiaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_VillaRicaGeorgiaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_VillaRicaGeorgiaIndustrialBuildingMember" xlink:to="lab_good_VillaRicaGeorgiaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberOfTrustSharesExchangedForGeneralPartnershipInterest_0360539d-a046-4d42-af75-7ab7a35cee01_terseLabel_en-US" xlink:label="lab_good_NumberOfTrustSharesExchangedForGeneralPartnershipInterest" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of trust shares exchanged for general partnership interest (in shares) </link:label>

<link:label id="lab_good_NumberOfTrustSharesExchangedForGeneralPartnershipInterest_label_en-US" xlink:label="lab_good_NumberOfTrustSharesExchangedForGeneralPartnershipInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Trust Shares Exchanged For General Partnership Interest </link:label>

<link:label id="lab_good_NumberOfTrustSharesExchangedForGeneralPartnershipInterest_documentation_en-US" xlink:label="lab_good_NumberOfTrustSharesExchangedForGeneralPartnershipInterest" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of trust shares exchanged for general partnership interest. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberOfTrustSharesExchangedForGeneralPartnershipInterest" xlink:href="good-20221231.xsd#good_NumberOfTrustSharesExchangedForGeneralPartnershipInterest"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberOfTrustSharesExchangedForGeneralPartnershipInterest" xlink:to="lab_good_NumberOfTrustSharesExchangedForGeneralPartnershipInterest" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_InterestRateSwapMember_854ba40e-b40e-4e62-b854-8d064fa26362_terseLabel_en-US" xlink:label="lab_us-gaap_InterestRateSwapMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest rate swaps </link:label>

<link:label id="lab_us-gaap_InterestRateSwapMember_label_en-US" xlink:label="lab_us-gaap_InterestRateSwapMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest Rate Swap [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateSwapMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestRateSwapMember" xlink:to="lab_us-gaap_InterestRateSwapMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_MaximumAggregateSalesPriceOfSharesToBeIssuedUnderOpenMarketSaleAgreement_9caab21d-92d3-4e32-86e9-ddcb6b1e13ac_terseLabel_en-US" xlink:label="lab_good_MaximumAggregateSalesPriceOfSharesToBeIssuedUnderOpenMarketSaleAgreement" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Maximum aggregate sales price of shares to be issued under open market sale agreement </link:label>

<link:label id="lab_good_MaximumAggregateSalesPriceOfSharesToBeIssuedUnderOpenMarketSaleAgreement_label_en-US" xlink:label="lab_good_MaximumAggregateSalesPriceOfSharesToBeIssuedUnderOpenMarketSaleAgreement" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Maximum Aggregate Sales Price Of Shares To Be Issued Under Open Market Sale Agreement </link:label>

<link:label id="lab_good_MaximumAggregateSalesPriceOfSharesToBeIssuedUnderOpenMarketSaleAgreement_documentation_en-US" xlink:label="lab_good_MaximumAggregateSalesPriceOfSharesToBeIssuedUnderOpenMarketSaleAgreement" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Maximum aggregate sales price of shares to be issued under open market sale agreement. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_MaximumAggregateSalesPriceOfSharesToBeIssuedUnderOpenMarketSaleAgreement" xlink:href="good-20221231.xsd#good_MaximumAggregateSalesPriceOfSharesToBeIssuedUnderOpenMarketSaleAgreement"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_MaximumAggregateSalesPriceOfSharesToBeIssuedUnderOpenMarketSaleAgreement" xlink:to="lab_good_MaximumAggregateSalesPriceOfSharesToBeIssuedUnderOpenMarketSaleAgreement" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_366207f2-a0ca-4061-90b6-e1fd93bccc0f_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2027 </link:label>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, to be Paid, Year Five </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:type="arc" order="1"/>

<link:label id="lab_good_PeruIllinoisIndustrialBuildingMember_fb7656ef-a9d3-47b5-9757-d756fb662bf4_terseLabel_en-US" xlink:label="lab_good_PeruIllinoisIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Peru, Illinois Industrial Building </link:label>

<link:label id="lab_good_PeruIllinoisIndustrialBuildingMember_label_en-US" xlink:label="lab_good_PeruIllinoisIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Peru, Illinois Industrial Building [Member] </link:label>

<link:label id="lab_good_PeruIllinoisIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_PeruIllinoisIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Peru, Illinois Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PeruIllinoisIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_PeruIllinoisIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PeruIllinoisIndustrialBuildingMember" xlink:to="lab_good_PeruIllinoisIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_DealerManagementFeeGrossProceedsPercentage_431eadbe-c5fc-4ba9-a083-0d480860579f_terseLabel_en-US" xlink:label="lab_good_DealerManagementFeeGrossProceedsPercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dealer management fee </link:label>

<link:label id="lab_good_DealerManagementFeeGrossProceedsPercentage_label_en-US" xlink:label="lab_good_DealerManagementFeeGrossProceedsPercentage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dealer Management Fee, Gross Proceeds, Percentage </link:label>

<link:label id="lab_good_DealerManagementFeeGrossProceedsPercentage_documentation_en-US" xlink:label="lab_good_DealerManagementFeeGrossProceedsPercentage" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dealer Management Fee, Gross Proceeds, Percentage </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DealerManagementFeeGrossProceedsPercentage" xlink:href="good-20221231.xsd#good_DealerManagementFeeGrossProceedsPercentage"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DealerManagementFeeGrossProceedsPercentage" xlink:to="lab_good_DealerManagementFeeGrossProceedsPercentage" xlink:type="arc" order="1"/>

<link:label id="lab_good_OrdinaryIncomeMember_c142c7d8-1618-4ac0-9b1e-a185dc11d32b_terseLabel_en-US" xlink:label="lab_good_OrdinaryIncomeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ordinary Income </link:label>

<link:label id="lab_good_OrdinaryIncomeMember_label_en-US" xlink:label="lab_good_OrdinaryIncomeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ordinary Income [Member] </link:label>

<link:label id="lab_good_OrdinaryIncomeMember_documentation_en-US" xlink:label="lab_good_OrdinaryIncomeMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ordinary income. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_OrdinaryIncomeMember" xlink:href="good-20221231.xsd#good_OrdinaryIncomeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_OrdinaryIncomeMember" xlink:to="lab_good_OrdinaryIncomeMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_IncentiveFeeWaived_e4b20af4-f069-4f98-acd2-ff98be0a2801_terseLabel_en-US" xlink:label="lab_good_IncentiveFeeWaived" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Portion of incentive fee waived </link:label>

<link:label id="lab_good_IncentiveFeeWaived_label_en-US" xlink:label="lab_good_IncentiveFeeWaived" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Incentive Fee Waived </link:label>

<link:label id="lab_good_IncentiveFeeWaived_documentation_en-US" xlink:label="lab_good_IncentiveFeeWaived" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Incentive Fee Waived </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_IncentiveFeeWaived" xlink:href="good-20221231.xsd#good_IncentiveFeeWaived"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_IncentiveFeeWaived" xlink:to="lab_good_IncentiveFeeWaived" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberOfPropertiesAcquired_2a2af39c-0adf-440d-80d5-c1102dcd25e4_terseLabel_en-US" xlink:label="lab_good_NumberOfPropertiesAcquired" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of properties acquired </link:label>

<link:label id="lab_good_NumberOfPropertiesAcquired_label_en-US" xlink:label="lab_good_NumberOfPropertiesAcquired" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Properties Acquired </link:label>

<link:label id="lab_good_NumberOfPropertiesAcquired_documentation_en-US" xlink:label="lab_good_NumberOfPropertiesAcquired" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of properties acquired. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberOfPropertiesAcquired" xlink:href="good-20221231.xsd#good_NumberOfPropertiesAcquired"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberOfPropertiesAcquired" xlink:to="lab_good_NumberOfPropertiesAcquired" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberOfMortgageNotesPayable_7553b854-aa39-4299-8b9a-75f0495be046_terseLabel_en-US" xlink:label="lab_good_NumberOfMortgageNotesPayable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of mortgage notes payable </link:label>

<link:label id="lab_good_NumberOfMortgageNotesPayable_label_en-US" xlink:label="lab_good_NumberOfMortgageNotesPayable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Mortgage Notes Payable </link:label>

<link:label id="lab_good_NumberOfMortgageNotesPayable_documentation_en-US" xlink:label="lab_good_NumberOfMortgageNotesPayable" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of mortgage notes payable. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberOfMortgageNotesPayable" xlink:href="good-20221231.xsd#good_NumberOfMortgageNotesPayable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberOfMortgageNotesPayable" xlink:to="lab_good_NumberOfMortgageNotesPayable" xlink:type="arc" order="1"/>

<link:label id="lab_good_LineOfCreditFacilityDelayedFundingComponent_03cb29db-e9c7-4740-9979-1444b5116c09_terseLabel_en-US" xlink:label="lab_good_LineOfCreditFacilityDelayedFundingComponent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of credit facility, delayed funding component </link:label>

<link:label id="lab_good_LineOfCreditFacilityDelayedFundingComponent_label_en-US" xlink:label="lab_good_LineOfCreditFacilityDelayedFundingComponent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of Credit Facility, Delayed Funding Component </link:label>

<link:label id="lab_good_LineOfCreditFacilityDelayedFundingComponent_documentation_en-US" xlink:label="lab_good_LineOfCreditFacilityDelayedFundingComponent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of Credit Facility, Delayed Funding Component </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_LineOfCreditFacilityDelayedFundingComponent" xlink:href="good-20221231.xsd#good_LineOfCreditFacilityDelayedFundingComponent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_LineOfCreditFacilityDelayedFundingComponent" xlink:to="lab_good_LineOfCreditFacilityDelayedFundingComponent" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_EarningsPerShareTextBlock_6256e6a1-b32f-4d49-abcd-68b6cad2c2c4_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> (Loss) Earnings per Share of Common Stock </link:label>

<link:label id="lab_us-gaap_EarningsPerShareTextBlock_label_en-US" xlink:label="lab_us-gaap_EarningsPerShareTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings Per Share [Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerShareTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerShareTextBlock" xlink:to="lab_us-gaap_EarningsPerShareTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OtherPreferredStockDividendsAndAdjustments_899b88e6-0792-4ada-981b-7c04cf04ab3a_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_OtherPreferredStockDividendsAndAdjustments" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred stock adjustments </link:label>

<link:label id="lab_us-gaap_OtherPreferredStockDividendsAndAdjustments_label_en-US" xlink:label="lab_us-gaap_OtherPreferredStockDividendsAndAdjustments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Preferred Stock Dividends and Adjustments </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPreferredStockDividendsAndAdjustments" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherPreferredStockDividendsAndAdjustments"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherPreferredStockDividendsAndAdjustments" xlink:to="lab_us-gaap_OtherPreferredStockDividendsAndAdjustments" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_InterestRateCapMember_43bf8399-a529-4461-98f7-6752b3d60c9c_terseLabel_en-US" xlink:label="lab_us-gaap_InterestRateCapMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest rate caps </link:label>

<link:label id="lab_us-gaap_InterestRateCapMember_label_en-US" xlink:label="lab_us-gaap_InterestRateCapMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest Rate Cap [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateCapMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateCapMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestRateCapMember" xlink:to="lab_us-gaap_InterestRateCapMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_a6710cea-0fe8-449b-b8b2-805d9da5276b_terseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Assets disposed of by sale </link:label>

<link:label id="lab_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_label_en-US" xlink:label="lab_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:to="lab_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_c7c532c0-2ec9-4b2b-9899-fc0e881a8f52_totalLabel_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Comprehensive income </link:label>

<link:label id="lab_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_label_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:to="lab_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:type="arc" order="1"/>

<link:label id="lab_good_JacksonvilleFloridaIndustrialBuildingMember_8e3cd212-8b24-4bae-9382-e7a85d75a1ff_terseLabel_en-US" xlink:label="lab_good_JacksonvilleFloridaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Jacksonville, Florida Industrial Building </link:label>

<link:label id="lab_good_JacksonvilleFloridaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_JacksonvilleFloridaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Jacksonville, Florida Industrial Building [Member] </link:label>

<link:label id="lab_good_JacksonvilleFloridaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_JacksonvilleFloridaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Jacksonville, Florida Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_JacksonvilleFloridaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_JacksonvilleFloridaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_JacksonvilleFloridaIndustrialBuildingMember" xlink:to="lab_good_JacksonvilleFloridaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_CharlotteNorthCarolinaIndustrialBuildingMember_5ebb3530-fbb7-469b-8da0-8e2df1a07313_terseLabel_en-US" xlink:label="lab_good_CharlotteNorthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Charlotte, North Carolina Industrial Building </link:label>

<link:label id="lab_good_CharlotteNorthCarolinaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_CharlotteNorthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Charlotte, North Carolina Industrial Building [Member] </link:label>

<link:label id="lab_good_CharlotteNorthCarolinaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_CharlotteNorthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Charlotte, North Carolina Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CharlotteNorthCarolinaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_CharlotteNorthCarolinaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CharlotteNorthCarolinaIndustrialBuildingMember" xlink:to="lab_good_CharlotteNorthCarolinaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_VanceAlabamaIndustrialBuildingMember_8b4809f2-cd85-40a2-a2ce-487d909aae3c_terseLabel_en-US" xlink:label="lab_good_VanceAlabamaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vance, Alabama Industrial Building </link:label>

<link:label id="lab_good_VanceAlabamaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_VanceAlabamaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vance Alabama Industrial Building [Member] </link:label>

<link:label id="lab_good_VanceAlabamaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_VanceAlabamaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vance Alabama Industrial Building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_VanceAlabamaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_VanceAlabamaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_VanceAlabamaIndustrialBuildingMember" xlink:to="lab_good_VanceAlabamaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAtCost_54107d4a-49e4-423f-9363-ab0759b2963d_verboseLabel_en-US" xlink:label="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAtCost" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real estate held for sale, gross </link:label>

<link:label id="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAtCost_label_en-US" xlink:label="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAtCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal group including discontinued operation real estate investment property at cost </link:label>

<link:label id="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAtCost_documentation_en-US" xlink:label="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAtCost" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal group including discontinued operation real estate investment property at cost. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAtCost" xlink:href="good-20221231.xsd#good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAtCost"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAtCost" xlink:to="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyAtCost" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesNewIssues_08fddb22-e041-48b9-b618-3926e5f983b1_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Issuance of Series A, B and F preferred stock and common stock, net (in shares) </link:label>

<link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesNewIssues_label_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Issued During Period, Shares, New Issues </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:to="lab_us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:type="arc" order="1"/>

<link:label id="lab_good_CommonStockATMProgramMember_ac76f5db-fbbb-4274-9a96-b573bb677cf7_terseLabel_en-US" xlink:label="lab_good_CommonStockATMProgramMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock ATM Program </link:label>

<link:label id="lab_good_CommonStockATMProgramMember_label_en-US" xlink:label="lab_good_CommonStockATMProgramMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock ATM Program [Member] </link:label>

<link:label id="lab_good_CommonStockATMProgramMember_documentation_en-US" xlink:label="lab_good_CommonStockATMProgramMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock ATM Program [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CommonStockATMProgramMember" xlink:href="good-20221231.xsd#good_CommonStockATMProgramMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CommonStockATMProgramMember" xlink:to="lab_good_CommonStockATMProgramMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberOfAssetsHeldForSale_67b19171-fa24-49fb-8e03-dc3a2da92e36_terseLabel_en-US" xlink:label="lab_good_NumberOfAssetsHeldForSale" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of assets held for sale </link:label>

<link:label id="lab_good_NumberOfAssetsHeldForSale_label_en-US" xlink:label="lab_good_NumberOfAssetsHeldForSale" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Assets Held For Sale </link:label>

<link:label id="lab_good_NumberOfAssetsHeldForSale_documentation_en-US" xlink:label="lab_good_NumberOfAssetsHeldForSale" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Assets Held For Sale </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberOfAssetsHeldForSale" xlink:href="good-20221231.xsd#good_NumberOfAssetsHeldForSale"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberOfAssetsHeldForSale" xlink:to="lab_good_NumberOfAssetsHeldForSale" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_TemporaryEquitySharesAuthorized_e4179483-2294-4498-9817-de5dc20898b1_terseLabel_en-US" xlink:label="lab_us-gaap_TemporaryEquitySharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Redeemable preferred stock, shares authorized (in shares) </link:label>

<link:label id="lab_us-gaap_TemporaryEquitySharesAuthorized_label_en-US" xlink:label="lab_us-gaap_TemporaryEquitySharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Temporary Equity, Shares Authorized </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquitySharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TemporaryEquitySharesAuthorized"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TemporaryEquitySharesAuthorized" xlink:to="lab_us-gaap_TemporaryEquitySharesAuthorized" xlink:type="arc" order="1"/>

<link:label id="lab_good_HuntsvilleAlabamaIndustrialBuildingMember_d17c2513-775c-43a3-ac0d-db03900fc909_terseLabel_en-US" xlink:label="lab_good_HuntsvilleAlabamaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Huntsville, Alabama Industrial Building </link:label>

<link:label id="lab_good_HuntsvilleAlabamaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_HuntsvilleAlabamaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Huntsville, Alabama Industrial Building [Member] </link:label>

<link:label id="lab_good_HuntsvilleAlabamaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_HuntsvilleAlabamaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Huntsville, Alabama Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_HuntsvilleAlabamaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_HuntsvilleAlabamaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_HuntsvilleAlabamaIndustrialBuildingMember" xlink:to="lab_good_HuntsvilleAlabamaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CustomerRelationshipsMember_7349bcc6-1968-4947-b743-f9aeaecb700b_terseLabel_en-US" xlink:label="lab_us-gaap_CustomerRelationshipsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Customer Relationships </link:label>

<link:label id="lab_us-gaap_CustomerRelationshipsMember_label_en-US" xlink:label="lab_us-gaap_CustomerRelationshipsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Customer Relationships [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CustomerRelationshipsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CustomerRelationshipsMember" xlink:to="lab_us-gaap_CustomerRelationshipsMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_WeightedAverageAmortizationPeriodForIntangibleAssetsAcquiredTableTextBlock_296e539d-96b8-4685-b97c-7ef6853bdba4_terseLabel_en-US" xlink:label="lab_good_WeightedAverageAmortizationPeriodForIntangibleAssetsAcquiredTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Amortization Period for Intangible Assets Acquired and Liabilities Assumed </link:label>

<link:label id="lab_good_WeightedAverageAmortizationPeriodForIntangibleAssetsAcquiredTableTextBlock_label_en-US" xlink:label="lab_good_WeightedAverageAmortizationPeriodForIntangibleAssetsAcquiredTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Amortization Period For Intangible Assets Acquired [Table Text Block] </link:label>

<link:label id="lab_good_WeightedAverageAmortizationPeriodForIntangibleAssetsAcquiredTableTextBlock_documentation_en-US" xlink:label="lab_good_WeightedAverageAmortizationPeriodForIntangibleAssetsAcquiredTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted average amortization period for intangible assets acquired. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_WeightedAverageAmortizationPeriodForIntangibleAssetsAcquiredTableTextBlock" xlink:href="good-20221231.xsd#good_WeightedAverageAmortizationPeriodForIntangibleAssetsAcquiredTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_WeightedAverageAmortizationPeriodForIntangibleAssetsAcquiredTableTextBlock" xlink:to="lab_good_WeightedAverageAmortizationPeriodForIntangibleAssetsAcquiredTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_CovingtonGeorgiaOfficeBuildingMember_691aa322-4054-4628-a4af-6f43221ed259_terseLabel_en-US" xlink:label="lab_good_CovingtonGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Covington, Georgia Medical Office Building </link:label>

<link:label id="lab_good_CovingtonGeorgiaOfficeBuildingMember_label_en-US" xlink:label="lab_good_CovingtonGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Covington Georgia Office Building [Member] </link:label>

<link:label id="lab_good_CovingtonGeorgiaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_CovingtonGeorgiaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Covington Georgia office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CovingtonGeorgiaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_CovingtonGeorgiaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CovingtonGeorgiaOfficeBuildingMember" xlink:to="lab_good_CovingtonGeorgiaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityAddressCityOrTown_5a93df93-9d81-44d7-96c6-5b9baaea40a2_terseLabel_en-US" xlink:label="lab_dei_EntityAddressCityOrTown" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, City or Town </link:label>

<link:label id="lab_dei_EntityAddressCityOrTown_label_en-US" xlink:label="lab_dei_EntityAddressCityOrTown" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, City or Town </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressCityOrTown"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityAddressCityOrTown" xlink:to="lab_dei_EntityAddressCityOrTown" xlink:type="arc" order="1"/>

<link:label id="lab_good_NoncontrollingInterestOwnershipByNoncontrollingOwnersNumberOfSharesOutstanding_6ef70ced-0b50-416b-888b-88f9ca6cc64e_terseLabel_en-US" xlink:label="lab_good_NoncontrollingInterestOwnershipByNoncontrollingOwnersNumberOfSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ownership by noncontrolling owners, shares outstanding (in shares) </link:label>

<link:label id="lab_good_NoncontrollingInterestOwnershipByNoncontrollingOwnersNumberOfSharesOutstanding_label_en-US" xlink:label="lab_good_NoncontrollingInterestOwnershipByNoncontrollingOwnersNumberOfSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncontrolling Interest, Ownership by Noncontrolling Owners, Number of Shares, Outstanding </link:label>

<link:label id="lab_good_NoncontrollingInterestOwnershipByNoncontrollingOwnersNumberOfSharesOutstanding_documentation_en-US" xlink:label="lab_good_NoncontrollingInterestOwnershipByNoncontrollingOwnersNumberOfSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncontrolling Interest, Ownership by Noncontrolling Owners, Number of Shares, Outstanding </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NoncontrollingInterestOwnershipByNoncontrollingOwnersNumberOfSharesOutstanding" xlink:href="good-20221231.xsd#good_NoncontrollingInterestOwnershipByNoncontrollingOwnersNumberOfSharesOutstanding"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NoncontrollingInterestOwnershipByNoncontrollingOwnersNumberOfSharesOutstanding" xlink:to="lab_good_NoncontrollingInterestOwnershipByNoncontrollingOwnersNumberOfSharesOutstanding" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OperatingExpensesAbstract_b9691707-a39c-4589-b0ce-dd545358d1fe_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingExpensesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating expenses </link:label>

<link:label id="lab_us-gaap_OperatingExpensesAbstract_label_en-US" xlink:label="lab_us-gaap_OperatingExpensesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Expenses [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingExpensesAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingExpensesAbstract" xlink:to="lab_us-gaap_OperatingExpensesAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_BigFlatsNewYorkIndustrialBuildingMember_55d1d645-6ccc-48ce-a9e9-102f20f13e6b_terseLabel_en-US" xlink:label="lab_good_BigFlatsNewYorkIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Big Flats, New York Industrial Building </link:label>

<link:label id="lab_good_BigFlatsNewYorkIndustrialBuildingMember_label_en-US" xlink:label="lab_good_BigFlatsNewYorkIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Big Flats New York Industrial Building [Member] </link:label>

<link:label id="lab_good_BigFlatsNewYorkIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_BigFlatsNewYorkIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Big Flats New York industrial building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BigFlatsNewYorkIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_BigFlatsNewYorkIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BigFlatsNewYorkIndustrialBuildingMember" xlink:to="lab_good_BigFlatsNewYorkIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_RealEstateAndAccumulatedDepreciationSecondYearOfConstructionOrImprovements_27d4d00b-ef9a-4fd8-92d2-7c9821babbe9_terseLabel_en-US" xlink:label="lab_good_RealEstateAndAccumulatedDepreciationSecondYearOfConstructionOrImprovements" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Year construction/improvements one </link:label>

<link:label id="lab_good_RealEstateAndAccumulatedDepreciationSecondYearOfConstructionOrImprovements_label_en-US" xlink:label="lab_good_RealEstateAndAccumulatedDepreciationSecondYearOfConstructionOrImprovements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate And Accumulated Depreciation Second Year Of Construction Or Improvements </link:label>

<link:label id="lab_good_RealEstateAndAccumulatedDepreciationSecondYearOfConstructionOrImprovements_documentation_en-US" xlink:label="lab_good_RealEstateAndAccumulatedDepreciationSecondYearOfConstructionOrImprovements" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real estate and accumulated depreciation, year of construction one. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_RealEstateAndAccumulatedDepreciationSecondYearOfConstructionOrImprovements" xlink:href="good-20221231.xsd#good_RealEstateAndAccumulatedDepreciationSecondYearOfConstructionOrImprovements"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_RealEstateAndAccumulatedDepreciationSecondYearOfConstructionOrImprovements" xlink:to="lab_good_RealEstateAndAccumulatedDepreciationSecondYearOfConstructionOrImprovements" xlink:type="arc" order="1"/>

<link:label id="lab_good_PacificMissouriIndustrialBuildingTwoMember_2ec4efbb-7927-400b-84b0-323ec79204a0_terseLabel_en-US" xlink:label="lab_good_PacificMissouriIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pacific, Missouri Industrial Building Two </link:label>

<link:label id="lab_good_PacificMissouriIndustrialBuildingTwoMember_label_en-US" xlink:label="lab_good_PacificMissouriIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pacific, Missouri Industrial Building Two [Member] </link:label>

<link:label id="lab_good_PacificMissouriIndustrialBuildingTwoMember_documentation_en-US" xlink:label="lab_good_PacificMissouriIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pacific, Missouri Industrial Building Two </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PacificMissouriIndustrialBuildingTwoMember" xlink:href="good-20221231.xsd#good_PacificMissouriIndustrialBuildingTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PacificMissouriIndustrialBuildingTwoMember" xlink:to="lab_good_PacificMissouriIndustrialBuildingTwoMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_CantonOhioOfficeAndWarehouseBuildingMember_3a392534-4986-42e3-8b12-3270457237ed_terseLabel_en-US" xlink:label="lab_good_CantonOhioOfficeAndWarehouseBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Canton, Ohio Office Building </link:label>

<link:label id="lab_good_CantonOhioOfficeAndWarehouseBuildingMember_label_en-US" xlink:label="lab_good_CantonOhioOfficeAndWarehouseBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Canton Ohio Office And Warehouse Building [Member] </link:label>

<link:label id="lab_good_CantonOhioOfficeAndWarehouseBuildingMember_documentation_en-US" xlink:label="lab_good_CantonOhioOfficeAndWarehouseBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Canton Ohio office and warehouse building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CantonOhioOfficeAndWarehouseBuildingMember" xlink:href="good-20221231.xsd#good_CantonOhioOfficeAndWarehouseBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CantonOhioOfficeAndWarehouseBuildingMember" xlink:to="lab_good_CantonOhioOfficeAndWarehouseBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_MinorityInterest_8e89c55c-412b-45b4-a600-c4c19e5680c1_terseLabel_en-US" xlink:label="lab_us-gaap_MinorityInterest" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> OP Units held by Non-controlling OP Unitholders </link:label>

<link:label id="lab_us-gaap_MinorityInterest_label_en-US" xlink:label="lab_us-gaap_MinorityInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stockholders' Equity Attributable to Noncontrolling Interest </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterest"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MinorityInterest" xlink:to="lab_us-gaap_MinorityInterest" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StatementOfFinancialPositionAbstract_e1ea5946-12ac-4dd0-bd6e-75f77ba20e19_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfFinancialPositionAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement of Financial Position [Abstract] </link:label>

<link:label id="lab_us-gaap_StatementOfFinancialPositionAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfFinancialPositionAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement of Financial Position [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementOfFinancialPositionAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract" xlink:to="lab_us-gaap_StatementOfFinancialPositionAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears_51d71cf4-8138-4b9d-8c85-a89e686fd525_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2026 </link:label>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessor, Operating Lease, Payment to be Received, Year Four </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DeferredFinanceCostsNet_eec61738-6243-49eb-87ff-60bdb40403b5_negatedLabel_en-US" xlink:label="lab_us-gaap_DeferredFinanceCostsNet" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred financing costs, net </link:label>

<link:label id="lab_us-gaap_DeferredFinanceCostsNet_e9343f31-f652-4830-b84f-03fd369b944b_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredFinanceCostsNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred financing costs </link:label>

<link:label id="lab_us-gaap_DeferredFinanceCostsNet_label_en-US" xlink:label="lab_us-gaap_DeferredFinanceCostsNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Issuance Costs, Net </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredFinanceCostsNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredFinanceCostsNet" xlink:to="lab_us-gaap_DeferredFinanceCostsNet" xlink:type="arc" order="1"/>

<link:label id="lab_dei_AuditorName_2b87f8a1-adef-477f-aa00-5f123ef891a4_terseLabel_en-US" xlink:label="lab_dei_AuditorName" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Auditor Name </link:label>

<link:label id="lab_dei_AuditorName_label_en-US" xlink:label="lab_dei_AuditorName" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Auditor Name </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_AuditorName" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_AuditorName"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_AuditorName" xlink:to="lab_dei_AuditorName" xlink:type="arc" order="1"/>

<link:label id="lab_good_PortAllenLouisianaIndustrialBuildingMember_09e97c7a-176a-42a7-adf1-2e49a744a12f_terseLabel_en-US" xlink:label="lab_good_PortAllenLouisianaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Port Allen, Louisiana Industrial Building </link:label>

<link:label id="lab_good_PortAllenLouisianaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_PortAllenLouisianaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Port Allen, Louisiana Industrial Building [Member] </link:label>

<link:label id="lab_good_PortAllenLouisianaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_PortAllenLouisianaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Port Allen, Louisiana Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PortAllenLouisianaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_PortAllenLouisianaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PortAllenLouisianaIndustrialBuildingMember" xlink:to="lab_good_PortAllenLouisianaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_DebtInstrumentFloorOnVariableRate_d80b3c79-c98f-488b-b060-d5986edcc14f_terseLabel_en-US" xlink:label="lab_good_DebtInstrumentFloorOnVariableRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Floor on LIBOR </link:label>

<link:label id="lab_good_DebtInstrumentFloorOnVariableRate_label_en-US" xlink:label="lab_good_DebtInstrumentFloorOnVariableRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Floor on Variable Rate </link:label>

<link:label id="lab_good_DebtInstrumentFloorOnVariableRate_documentation_en-US" xlink:label="lab_good_DebtInstrumentFloorOnVariableRate" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Floor on Variable Rate </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DebtInstrumentFloorOnVariableRate" xlink:href="good-20221231.xsd#good_DebtInstrumentFloorOnVariableRate"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DebtInstrumentFloorOnVariableRate" xlink:to="lab_good_DebtInstrumentFloorOnVariableRate" xlink:type="arc" order="1"/>

<link:label id="lab_good_PurchasePriceOfAcquiredProperty_cdff9b41-66b9-4c8b-8e1e-c8833f0a7e5c_terseLabel_en-US" xlink:label="lab_good_PurchasePriceOfAcquiredProperty" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate Purchase Price </link:label>

<link:label id="lab_good_PurchasePriceOfAcquiredProperty_0d1e98d8-247b-419a-a6d8-ab12554622b7_totalLabel_en-US" xlink:label="lab_good_PurchasePriceOfAcquiredProperty" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total Purchase Price </link:label>

<link:label id="lab_good_PurchasePriceOfAcquiredProperty_label_en-US" xlink:label="lab_good_PurchasePriceOfAcquiredProperty" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Purchase Price Of Acquired Property </link:label>

<link:label id="lab_good_PurchasePriceOfAcquiredProperty_documentation_en-US" xlink:label="lab_good_PurchasePriceOfAcquiredProperty" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Purchase price of acquired property. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PurchasePriceOfAcquiredProperty" xlink:href="good-20221231.xsd#good_PurchasePriceOfAcquiredProperty"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PurchasePriceOfAcquiredProperty" xlink:to="lab_good_PurchasePriceOfAcquiredProperty" xlink:type="arc" order="1"/>

<link:label id="lab_good_SpringfieldMissouriRetailLocationMember_d02c9428-b810-49cd-97ac-30b8dd64433b_terseLabel_en-US" xlink:label="lab_good_SpringfieldMissouriRetailLocationMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Springfield, Missouri Retail Location </link:label>

<link:label id="lab_good_SpringfieldMissouriRetailLocationMember_label_en-US" xlink:label="lab_good_SpringfieldMissouriRetailLocationMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Springfield Missouri Retail Location [Member] </link:label>

<link:label id="lab_good_SpringfieldMissouriRetailLocationMember_documentation_en-US" xlink:label="lab_good_SpringfieldMissouriRetailLocationMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Springfield Missouri retail location. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SpringfieldMissouriRetailLocationMember" xlink:href="good-20221231.xsd#good_SpringfieldMissouriRetailLocationMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SpringfieldMissouriRetailLocationMember" xlink:to="lab_good_SpringfieldMissouriRetailLocationMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_FiveYearTermLoanFacilityMember_20669f4d-77d6-47da-a5a6-1273b9fe0295_terseLabel_en-US" xlink:label="lab_good_FiveYearTermLoanFacilityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Five year term loan facility </link:label>

<link:label id="lab_good_FiveYearTermLoanFacilityMember_label_en-US" xlink:label="lab_good_FiveYearTermLoanFacilityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Five Year Term Loan Facility [Member] </link:label>

<link:label id="lab_good_FiveYearTermLoanFacilityMember_documentation_en-US" xlink:label="lab_good_FiveYearTermLoanFacilityMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Five Year Term Loan Facility [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_FiveYearTermLoanFacilityMember" xlink:href="good-20221231.xsd#good_FiveYearTermLoanFacilityMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_FiveYearTermLoanFacilityMember" xlink:to="lab_good_FiveYearTermLoanFacilityMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_BuildingImprovementsMember_0f0657f2-5b80-496f-a5f6-09df7bc799c1_terseLabel_en-US" xlink:label="lab_us-gaap_BuildingImprovementsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Improvements </link:label>

<link:label id="lab_us-gaap_BuildingImprovementsMember_label_en-US" xlink:label="lab_us-gaap_BuildingImprovementsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Building Improvements [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingImprovementsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BuildingImprovementsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BuildingImprovementsMember" xlink:to="lab_us-gaap_BuildingImprovementsMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DisposalGroupClassificationAxis_0fb89447-24c6-4d5b-9bb4-94a2859504e7_terseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupClassificationAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Group Classification [Axis] </link:label>

<link:label id="lab_us-gaap_DisposalGroupClassificationAxis_label_en-US" xlink:label="lab_us-gaap_DisposalGroupClassificationAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Group Classification [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisposalGroupClassificationAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis" xlink:to="lab_us-gaap_DisposalGroupClassificationAxis" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RestrictedCashAndCashEquivalents_c84d44c1-7b29-48ea-bca5-4393e27bcdd4_terseLabel_en-US" xlink:label="lab_us-gaap_RestrictedCashAndCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Restricted cash </link:label>

<link:label id="lab_us-gaap_RestrictedCashAndCashEquivalents_label_en-US" xlink:label="lab_us-gaap_RestrictedCashAndCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Restricted Cash and Cash Equivalents </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalents" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedCashAndCashEquivalents"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalents" xlink:to="lab_us-gaap_RestrictedCashAndCashEquivalents" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityInformationLineItems_ca8e4b1e-2b51-47e2-96a3-abc04d632e3c_terseLabel_en-US" xlink:label="lab_dei_EntityInformationLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Information [Line Items] </link:label>

<link:label id="lab_dei_EntityInformationLineItems_label_en-US" xlink:label="lab_dei_EntityInformationLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Information [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityInformationLineItems" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityInformationLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityInformationLineItems" xlink:to="lab_dei_EntityInformationLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand_686be9c1-ff74-4a22-9ad9-6850f6286901_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Land, initial cost </link:label>

<link:label id="lab_us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand_label_en-US" xlink:label="lab_us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand" xlink:to="lab_us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand" xlink:type="arc" order="1"/>

<link:label id="lab_good_HialeahFloridaIndustrialBuildingMember_aea8cf09-3344-427d-a88b-7c4e496c2d19_terseLabel_en-US" xlink:label="lab_good_HialeahFloridaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hialeah, Florida Industrial Building </link:label>

<link:label id="lab_good_HialeahFloridaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_HialeahFloridaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hialeah Florida Industrial Building [Member] </link:label>

<link:label id="lab_good_HialeahFloridaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_HialeahFloridaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hialeah Florida industrial building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_HialeahFloridaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_HialeahFloridaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_HialeahFloridaIndustrialBuildingMember" xlink:to="lab_good_HialeahFloridaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_PercentageOfFinancingFeeToAmountOfMortgage_4f870d43-4a39-4939-b04d-5992b91d21d9_terseLabel_en-US" xlink:label="lab_good_PercentageOfFinancingFeeToAmountOfMortgage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of the amount of the mortgage </link:label>

<link:label id="lab_good_PercentageOfFinancingFeeToAmountOfMortgage_label_en-US" xlink:label="lab_good_PercentageOfFinancingFeeToAmountOfMortgage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage Of Financing Fee To Amount Of Mortgage </link:label>

<link:label id="lab_good_PercentageOfFinancingFeeToAmountOfMortgage_documentation_en-US" xlink:label="lab_good_PercentageOfFinancingFeeToAmountOfMortgage" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of financing fee to amount of mortgage. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PercentageOfFinancingFeeToAmountOfMortgage" xlink:href="good-20221231.xsd#good_PercentageOfFinancingFeeToAmountOfMortgage"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PercentageOfFinancingFeeToAmountOfMortgage" xlink:to="lab_good_PercentageOfFinancingFeeToAmountOfMortgage" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LondonInterbankOfferedRateLIBORMember_56bc3e24-7cc3-4c4f-a673-be46ded1e7a2_terseLabel_en-US" xlink:label="lab_us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> LIBOR </link:label>

<link:label id="lab_us-gaap_LondonInterbankOfferedRateLIBORMember_label_en-US" xlink:label="lab_us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> London Interbank Offered Rate (LIBOR) [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:to="lab_us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock_d30b056d-fc30-4c83-b4c1-2ce50eb1c70c_terseLabel_en-US" xlink:label="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Organization, Basis of Presentation and Significant Accounting Policies </link:label>

<link:label id="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock_label_en-US" xlink:label="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock" xlink:to="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SubsequentEventsAbstract_3c1a5972-33c2-4e58-99d8-388c8394dac2_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsequent Events [Abstract] </link:label>

<link:label id="lab_us-gaap_SubsequentEventsAbstract_label_en-US" xlink:label="lab_us-gaap_SubsequentEventsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsequent Events [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventsAbstract" xlink:to="lab_us-gaap_SubsequentEventsAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_Revenues_56995072-906c-4792-9dce-c2a9a9d98877_totalLabel_en-US" xlink:label="lab_us-gaap_Revenues" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total operating revenues </link:label>

<link:label id="lab_us-gaap_Revenues_label_en-US" xlink:label="lab_us-gaap_Revenues" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenues </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Revenues"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Revenues" xlink:to="lab_us-gaap_Revenues" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_86a07f3b-6c09-4790-be1d-3629c5e59c59_verboseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Change in unrealized gain related to interest rate hedging instruments, net </link:label>

<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_582f5a7d-5722-4adc-aa39-091195901e11_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unrealized gain related to interest rate hedging instruments, net </link:label>

<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_7990675d-43df-4fbe-8aa4-94eaad613bc3_netLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amount of gain (loss), net, recognized in Comprehensive Income </link:label>

<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:to="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:type="arc" order="1"/>

<link:label id="lab_good_StockIssuedForPreferredStockDividends_5a79b5c0-9ea2-4047-b396-5f2512d48264_terseLabel_en-US" xlink:label="lab_good_StockIssuedForPreferredStockDividends" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividends paid on Series F Preferred Stock via additional share issuances </link:label>

<link:label id="lab_good_StockIssuedForPreferredStockDividends_label_en-US" xlink:label="lab_good_StockIssuedForPreferredStockDividends" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Issued For Preferred Stock Dividends </link:label>

<link:label id="lab_good_StockIssuedForPreferredStockDividends_documentation_en-US" xlink:label="lab_good_StockIssuedForPreferredStockDividends" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Issued For Preferred Stock Dividends </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_StockIssuedForPreferredStockDividends" xlink:href="good-20221231.xsd#good_StockIssuedForPreferredStockDividends"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_StockIssuedForPreferredStockDividends" xlink:to="lab_good_StockIssuedForPreferredStockDividends" xlink:type="arc" order="1"/>

<link:label id="lab_good_EquipmentAndFixturesMember_ee701482-8426-4de9-9fea-63df423d18c7_terseLabel_en-US" xlink:label="lab_good_EquipmentAndFixturesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equipment and Fixtures </link:label>

<link:label id="lab_good_EquipmentAndFixturesMember_label_en-US" xlink:label="lab_good_EquipmentAndFixturesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equipment And Fixtures [Member] </link:label>

<link:label id="lab_good_EquipmentAndFixturesMember_documentation_en-US" xlink:label="lab_good_EquipmentAndFixturesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equipment and fixtures. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_EquipmentAndFixturesMember" xlink:href="good-20221231.xsd#good_EquipmentAndFixturesMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_EquipmentAndFixturesMember" xlink:to="lab_good_EquipmentAndFixturesMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_OklahomaCityOklahomaMember_cf05f6c3-5e31-4d0e-9301-93f56a0de489_terseLabel_en-US" xlink:label="lab_good_OklahomaCityOklahomaMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Oklahoma City, Oklahoma </link:label>

<link:label id="lab_good_OklahomaCityOklahomaMember_label_en-US" xlink:label="lab_good_OklahomaCityOklahomaMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Oklahoma City, Oklahoma [Member] </link:label>

<link:label id="lab_good_OklahomaCityOklahomaMember_documentation_en-US" xlink:label="lab_good_OklahomaCityOklahomaMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Oklahoma City, Oklahoma </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_OklahomaCityOklahomaMember" xlink:href="good-20221231.xsd#good_OklahomaCityOklahomaMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_OklahomaCityOklahomaMember" xlink:to="lab_good_OklahomaCityOklahomaMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AmortizationOfIntangibleAssets_941842d7-b648-4757-a2ec-20269a3a16eb_terseLabel_en-US" xlink:label="lab_us-gaap_AmortizationOfIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total amortization expense related to intangible assets </link:label>

<link:label id="lab_us-gaap_AmortizationOfIntangibleAssets_4f7c782d-344e-4f0e-92cb-c1cec7e0fc07_verboseLabel_en-US" xlink:label="lab_us-gaap_AmortizationOfIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of intangible assets </link:label>

<link:label id="lab_us-gaap_AmortizationOfIntangibleAssets_label_en-US" xlink:label="lab_us-gaap_AmortizationOfIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of Intangible Assets </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AmortizationOfIntangibleAssets"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AmortizationOfIntangibleAssets" xlink:to="lab_us-gaap_AmortizationOfIntangibleAssets" xlink:type="arc" order="1"/>

<link:label id="lab_good_BairdGoldmanSachsStifelAndFifthThirdMember_9cedeed9-f962-4268-8540-02ecd654a098_terseLabel_en-US" xlink:label="lab_good_BairdGoldmanSachsStifelAndFifthThirdMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Baird, Goldman Sachs, Stifel, and Fifth Third </link:label>

<link:label id="lab_good_BairdGoldmanSachsStifelAndFifthThirdMember_label_en-US" xlink:label="lab_good_BairdGoldmanSachsStifelAndFifthThirdMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Baird, Goldman Sachs, Stifel, and Fifth Third [Member] </link:label>

<link:label id="lab_good_BairdGoldmanSachsStifelAndFifthThirdMember_documentation_en-US" xlink:label="lab_good_BairdGoldmanSachsStifelAndFifthThirdMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Baird, Goldman Sachs, Stifel, and Fifth Third </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BairdGoldmanSachsStifelAndFifthThirdMember" xlink:href="good-20221231.xsd#good_BairdGoldmanSachsStifelAndFifthThirdMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BairdGoldmanSachsStifelAndFifthThirdMember" xlink:to="lab_good_BairdGoldmanSachsStifelAndFifthThirdMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_InterestPaidNet_f3cedf57-21b9-4bee-80f5-d7b028914b83_terseLabel_en-US" xlink:label="lab_us-gaap_InterestPaidNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash paid during year for interest </link:label>

<link:label id="lab_us-gaap_InterestPaidNet_label_en-US" xlink:label="lab_us-gaap_InterestPaidNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest Paid, Excluding Capitalized Interest, Operating Activities </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestPaidNet" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestPaidNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestPaidNet" xlink:to="lab_us-gaap_InterestPaidNet" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_d4e89e85-4390-4f6b-a078-1a0e1207c250_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2025 </link:label>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, to be Paid, Year Three </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:type="arc" order="1"/>

<link:label id="lab_good_ScheduleOfRealEstateOwnedHeldForSaleLineItems_4e842f96-156d-41c9-be93-f998343e6168_terseLabel_en-US" xlink:label="lab_good_ScheduleOfRealEstateOwnedHeldForSaleLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Real Estate Owned Held For Sale [Line Items] </link:label>

<link:label id="lab_good_ScheduleOfRealEstateOwnedHeldForSaleLineItems_label_en-US" xlink:label="lab_good_ScheduleOfRealEstateOwnedHeldForSaleLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Real Estate Owned Held For Sale [Line Items] </link:label>

<link:label id="lab_good_ScheduleOfRealEstateOwnedHeldForSaleLineItems_documentation_en-US" xlink:label="lab_good_ScheduleOfRealEstateOwnedHeldForSaleLineItems" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of real estate owned held for sale line items. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ScheduleOfRealEstateOwnedHeldForSaleLineItems" xlink:href="good-20221231.xsd#good_ScheduleOfRealEstateOwnedHeldForSaleLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ScheduleOfRealEstateOwnedHeldForSaleLineItems" xlink:to="lab_good_ScheduleOfRealEstateOwnedHeldForSaleLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_good_AtlantaGeorgiaMember_be0f8e76-f835-4c9a-9f41-8c1d70f3e332_terseLabel_en-US" xlink:label="lab_good_AtlantaGeorgiaMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Atlanta, Georgia </link:label>

<link:label id="lab_good_AtlantaGeorgiaMember_label_en-US" xlink:label="lab_good_AtlantaGeorgiaMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Atlanta, Georgia [Member] </link:label>

<link:label id="lab_good_AtlantaGeorgiaMember_documentation_en-US" xlink:label="lab_good_AtlantaGeorgiaMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Atlanta, Georgia </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AtlantaGeorgiaMember" xlink:href="good-20221231.xsd#good_AtlantaGeorgiaMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AtlantaGeorgiaMember" xlink:to="lab_good_AtlantaGeorgiaMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_AssetImpairmentChargesExcludingIntangibleAssets_e07ee045-6cfa-43cd-a7ef-3d4bba8669b4_negatedTerseLabel_en-US" xlink:label="lab_good_AssetImpairmentChargesExcludingIntangibleAssets" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Impairments during period </link:label>

<link:label id="lab_good_AssetImpairmentChargesExcludingIntangibleAssets_label_en-US" xlink:label="lab_good_AssetImpairmentChargesExcludingIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset Impairment Charges, Excluding Intangible Assets </link:label>

<link:label id="lab_good_AssetImpairmentChargesExcludingIntangibleAssets_documentation_en-US" xlink:label="lab_good_AssetImpairmentChargesExcludingIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset Impairment Charges, Excluding Intangible Assets </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AssetImpairmentChargesExcludingIntangibleAssets" xlink:href="good-20221231.xsd#good_AssetImpairmentChargesExcludingIntangibleAssets"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AssetImpairmentChargesExcludingIntangibleAssets" xlink:to="lab_good_AssetImpairmentChargesExcludingIntangibleAssets" xlink:type="arc" order="1"/>

<link:label id="lab_good_AuroraColoradoIndustrialBuildingMember_7d9851bb-e81a-482f-ba97-b6dc838e0e74_terseLabel_en-US" xlink:label="lab_good_AuroraColoradoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aurora, Colorado Industrial Building </link:label>

<link:label id="lab_good_AuroraColoradoIndustrialBuildingMember_label_en-US" xlink:label="lab_good_AuroraColoradoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aurora, Colorado Industrial Building [Member] </link:label>

<link:label id="lab_good_AuroraColoradoIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_AuroraColoradoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aurora, Colorado Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AuroraColoradoIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_AuroraColoradoIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AuroraColoradoIndustrialBuildingMember" xlink:to="lab_good_AuroraColoradoIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_srt_RepurchaseAgreementCounterpartyNameDomain_a0a6573a-6438-4b41-9be9-46db424e1b7f_terseLabel_en-US" xlink:label="lab_srt_RepurchaseAgreementCounterpartyNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Counterparty Name [Domain] </link:label>

<link:label id="lab_srt_RepurchaseAgreementCounterpartyNameDomain_label_en-US" xlink:label="lab_srt_RepurchaseAgreementCounterpartyNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Counterparty Name [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain" xlink:to="lab_srt_RepurchaseAgreementCounterpartyNameDomain" xlink:type="arc" order="1"/>

<link:label id="lab_good_BridgetonAndVinelandNewJerseyMember_8195dcd3-5563-49fd-8bb5-9b91bf30e50c_terseLabel_en-US" xlink:label="lab_good_BridgetonAndVinelandNewJerseyMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Bridgeton and Vineland, New Jersey </link:label>

<link:label id="lab_good_BridgetonAndVinelandNewJerseyMember_label_en-US" xlink:label="lab_good_BridgetonAndVinelandNewJerseyMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Bridgeton and Vineland, New Jersey [Member] </link:label>

<link:label id="lab_good_BridgetonAndVinelandNewJerseyMember_documentation_en-US" xlink:label="lab_good_BridgetonAndVinelandNewJerseyMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Bridgeton and Vineland, New Jersey </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BridgetonAndVinelandNewJerseyMember" xlink:href="good-20221231.xsd#good_BridgetonAndVinelandNewJerseyMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BridgetonAndVinelandNewJerseyMember" xlink:to="lab_good_BridgetonAndVinelandNewJerseyMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StockholdersEquity_aabfbc0d-81f1-4615-ab13-4fe82e9a77c5_totalLabel_en-US" xlink:label="lab_us-gaap_StockholdersEquity" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> TOTAL STOCKHOLDERS' EQUITY </link:label>

<link:label id="lab_us-gaap_StockholdersEquity_label_en-US" xlink:label="lab_us-gaap_StockholdersEquity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stockholders' Equity Attributable to Parent </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquity"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockholdersEquity" xlink:to="lab_us-gaap_StockholdersEquity" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RedeemablePreferredStockDividends_8112fb2e-bb9d-4445-91fe-4a4f05e361fd_negatedLabel_en-US" xlink:label="lab_us-gaap_RedeemablePreferredStockDividends" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Distributions attributable to Series D, E, F, and G preferred stock </link:label>

<link:label id="lab_us-gaap_RedeemablePreferredStockDividends_label_en-US" xlink:label="lab_us-gaap_RedeemablePreferredStockDividends" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Redeemable Preferred Stock Dividends </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemablePreferredStockDividends" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RedeemablePreferredStockDividends"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RedeemablePreferredStockDividends" xlink:to="lab_us-gaap_RedeemablePreferredStockDividends" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AssetRetirementObligationsPolicy_45f5d239-7f1e-4967-8d03-b50ebaac5c84_terseLabel_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationsPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset Retirement Obligations </link:label>

<link:label id="lab_us-gaap_AssetRetirementObligationsPolicy_label_en-US" xlink:label="lab_us-gaap_AssetRetirementObligationsPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset Retirement Obligation [Policy Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetRetirementObligationsPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetRetirementObligationsPolicy"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetRetirementObligationsPolicy" xlink:to="lab_us-gaap_AssetRetirementObligationsPolicy" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_ecaffa58-a304-41f8-8dcf-107a49da0a1c_terseLabel_en-US" xlink:label="lab_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of shares sold (in shares) </link:label>

<link:label id="lab_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_label_en-US" xlink:label="lab_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale of Stock, Number of Shares Issued in Transaction </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:to="lab_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_24afbb7e-ee3b-4b7f-a897-44f52157188d_negatedLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-lived intangible assets, accumulated amortization </link:label>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets, Accumulated Amortization </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_060643d6-ba11-477d-a1ef-4696adf368c7_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2025 </link:label>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Asset, Expected Amortization, Year Three </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:type="arc" order="1"/>

<link:label id="lab_good_CreditFacilityMember_bbc9ee5b-7135-4679-9d61-c17595034207_terseLabel_en-US" xlink:label="lab_good_CreditFacilityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Credit Facility </link:label>

<link:label id="lab_good_CreditFacilityMember_label_en-US" xlink:label="lab_good_CreditFacilityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Credit Facility [Member] </link:label>

<link:label id="lab_good_CreditFacilityMember_documentation_en-US" xlink:label="lab_good_CreditFacilityMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Credit Facility </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CreditFacilityMember" xlink:href="good-20221231.xsd#good_CreditFacilityMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CreditFacilityMember" xlink:to="lab_good_CreditFacilityMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_d11c336a-39d7-4cc8-9c25-2aaa9e1806b5_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2027 </link:label>

<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Maturity, Year Five </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PaymentsOfDividends_31e6cb18-3f93-4fd2-af7d-4a32f8e2a1fa_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsOfDividends" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Distributions paid for common, senior common, preferred stock and Non-controlling OP Unitholders </link:label>

<link:label id="lab_us-gaap_PaymentsOfDividends_label_en-US" xlink:label="lab_us-gaap_PaymentsOfDividends" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments of Dividends </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividends" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsOfDividends"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsOfDividends" xlink:to="lab_us-gaap_PaymentsOfDividends" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_GainLossRelatedToLitigationSettlement_d37a8673-67a4-4159-a30c-6903d49fb467_terseLabel_en-US" xlink:label="lab_us-gaap_GainLossRelatedToLitigationSettlement" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gain on legal settlement </link:label>

<link:label id="lab_us-gaap_GainLossRelatedToLitigationSettlement_label_en-US" xlink:label="lab_us-gaap_GainLossRelatedToLitigationSettlement" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gain (Loss) Related to Litigation Settlement </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossRelatedToLitigationSettlement" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GainLossRelatedToLitigationSettlement"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GainLossRelatedToLitigationSettlement" xlink:to="lab_us-gaap_GainLossRelatedToLitigationSettlement" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears_b6db7f9b-120b-4956-83df-a9ba4d19e068_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2025 </link:label>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessor, Operating Lease, Payment to be Received, Year Three </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_InterestRateCashFlowHedgeAssetAtFairValue_e58c50bf-7d36-4182-b725-61579f2684e8_terseLabel_en-US" xlink:label="lab_us-gaap_InterestRateCashFlowHedgeAssetAtFairValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate Fair Value Asset </link:label>

<link:label id="lab_us-gaap_InterestRateCashFlowHedgeAssetAtFairValue_label_en-US" xlink:label="lab_us-gaap_InterestRateCashFlowHedgeAssetAtFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest Rate Cash Flow Hedge Asset at Fair Value </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateCashFlowHedgeAssetAtFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateCashFlowHedgeAssetAtFairValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestRateCashFlowHedgeAssetAtFairValue" xlink:to="lab_us-gaap_InterestRateCashFlowHedgeAssetAtFairValue" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LeaseCost_8e0f1d5b-0d94-4b15-b2a9-2493a06ad77c_totalLabel_en-US" xlink:label="lab_us-gaap_LeaseCost" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease payments </link:label>

<link:label id="lab_us-gaap_LeaseCost_label_en-US" xlink:label="lab_us-gaap_LeaseCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease, Cost </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseCost" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LeaseCost"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LeaseCost" xlink:to="lab_us-gaap_LeaseCost" xlink:type="arc" order="1"/>

<link:label id="lab_good_IndianapolisIndianaIndustrialBuildingThreeMember_931c18af-04a7-4927-9849-29bee920d949_terseLabel_en-US" xlink:label="lab_good_IndianapolisIndianaIndustrialBuildingThreeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indianapolis, Indiana Industrial Building Three </link:label>

<link:label id="lab_good_IndianapolisIndianaIndustrialBuildingThreeMember_label_en-US" xlink:label="lab_good_IndianapolisIndianaIndustrialBuildingThreeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indianapolis, Indiana Industrial Building Three [Member] </link:label>

<link:label id="lab_good_IndianapolisIndianaIndustrialBuildingThreeMember_documentation_en-US" xlink:label="lab_good_IndianapolisIndianaIndustrialBuildingThreeMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indianapolis, Indiana Industrial Building Three </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_IndianapolisIndianaIndustrialBuildingThreeMember" xlink:href="good-20221231.xsd#good_IndianapolisIndianaIndustrialBuildingThreeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_IndianapolisIndianaIndustrialBuildingThreeMember" xlink:to="lab_good_IndianapolisIndianaIndustrialBuildingThreeMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CommonStockMember_ad12353e-54cb-49f1-bcb7-98a4c39f4aff_verboseLabel_en-US" xlink:label="lab_us-gaap_CommonStockMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common and Senior Common Stock </link:label>

<link:label id="lab_us-gaap_CommonStockMember_8575a151-44fb-4e4f-b124-d8663b499d2c_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock and Non-controlling OP Units </link:label>

<link:label id="lab_us-gaap_CommonStockMember_label_en-US" xlink:label="lab_us-gaap_CommonStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockMember" xlink:to="lab_us-gaap_CommonStockMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_OttumwaIowaIndustrialMember_8a1fac06-c945-4014-98ac-34ba1f054a37_terseLabel_en-US" xlink:label="lab_good_OttumwaIowaIndustrialMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ottumwa, Iowa Industrial Building </link:label>

<link:label id="lab_good_OttumwaIowaIndustrialMember_label_en-US" xlink:label="lab_good_OttumwaIowaIndustrialMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ottumwa Iowa Industrial [Member] </link:label>

<link:label id="lab_good_OttumwaIowaIndustrialMember_documentation_en-US" xlink:label="lab_good_OttumwaIowaIndustrialMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ottumwa Iowa industrial. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_OttumwaIowaIndustrialMember" xlink:href="good-20221231.xsd#good_OttumwaIowaIndustrialMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_OttumwaIowaIndustrialMember" xlink:to="lab_good_OttumwaIowaIndustrialMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NumberOfReportableSegments_bc97efe2-8c89-4483-894e-fbdf46aa89d4_terseLabel_en-US" xlink:label="lab_us-gaap_NumberOfReportableSegments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of reporting segments </link:label>

<link:label id="lab_us-gaap_NumberOfReportableSegments_label_en-US" xlink:label="lab_us-gaap_NumberOfReportableSegments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Reportable Segments </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NumberOfReportableSegments"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NumberOfReportableSegments" xlink:to="lab_us-gaap_NumberOfReportableSegments" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LeaseCostTableTextBlock_676e754b-9267-41bb-9acb-bcf2760690b0_terseLabel_en-US" xlink:label="lab_us-gaap_LeaseCostTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease Revenue </link:label>

<link:label id="lab_us-gaap_LeaseCostTableTextBlock_label_en-US" xlink:label="lab_us-gaap_LeaseCostTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease, Cost [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseCostTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LeaseCostTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LeaseCostTableTextBlock" xlink:to="lab_us-gaap_LeaseCostTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RevenueRecognitionPolicyTextBlock_6ecf12bd-3829-456d-a8c2-8db6c8a5a337_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueRecognitionPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease Revenue </link:label>

<link:label id="lab_us-gaap_RevenueRecognitionPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_RevenueRecognitionPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue [Policy Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRecognitionPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueRecognitionPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueRecognitionPolicyTextBlock" xlink:to="lab_us-gaap_RevenueRecognitionPolicyTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_NoticePeriodForTerminationOfAgreementWithoutCause_d754703a-b05f-4de9-9921-960f3aa8628b_terseLabel_en-US" xlink:label="lab_good_NoticePeriodForTerminationOfAgreementWithoutCause" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Notice period for termination of agreement without cause </link:label>

<link:label id="lab_good_NoticePeriodForTerminationOfAgreementWithoutCause_label_en-US" xlink:label="lab_good_NoticePeriodForTerminationOfAgreementWithoutCause" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Notice Period For Termination Of Agreement Without Cause </link:label>

<link:label id="lab_good_NoticePeriodForTerminationOfAgreementWithoutCause_documentation_en-US" xlink:label="lab_good_NoticePeriodForTerminationOfAgreementWithoutCause" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Notice period for termination of agreement without cause. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NoticePeriodForTerminationOfAgreementWithoutCause" xlink:href="good-20221231.xsd#good_NoticePeriodForTerminationOfAgreementWithoutCause"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NoticePeriodForTerminationOfAgreementWithoutCause" xlink:to="lab_good_NoticePeriodForTerminationOfAgreementWithoutCause" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StatementTable_558107f4-b8be-4e0a-a903-dd09686029c9_terseLabel_en-US" xlink:label="lab_us-gaap_StatementTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement [Table] </link:label>

<link:label id="lab_us-gaap_StatementTable_label_en-US" xlink:label="lab_us-gaap_StatementTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementTable" xlink:to="lab_us-gaap_StatementTable" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock_12706738-10a3-4fb8-b43c-e96629e88820_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Summary Properties Sold </link:label>

<link:label id="lab_us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Groups, Including Discontinued Operations [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock" xlink:to="lab_us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_AssetAcquisitionEquityInterestRedeemedorRedeemableNumberofShares_ce8e4069-ad17-48de-b1e3-c6c1489a0327_terseLabel_en-US" xlink:label="lab_good_AssetAcquisitionEquityInterestRedeemedorRedeemableNumberofShares" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of units redeemed in acquisition (in shares) </link:label>

<link:label id="lab_good_AssetAcquisitionEquityInterestRedeemedorRedeemableNumberofShares_label_en-US" xlink:label="lab_good_AssetAcquisitionEquityInterestRedeemedorRedeemableNumberofShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset Acquisition, Equity Interest Redeemed or Redeemable, Number of Shares </link:label>

<link:label id="lab_good_AssetAcquisitionEquityInterestRedeemedorRedeemableNumberofShares_documentation_en-US" xlink:label="lab_good_AssetAcquisitionEquityInterestRedeemedorRedeemableNumberofShares" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset Acquisition, Equity Interest Redeemed or Redeemable, Number of Shares </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AssetAcquisitionEquityInterestRedeemedorRedeemableNumberofShares" xlink:href="good-20221231.xsd#good_AssetAcquisitionEquityInterestRedeemedorRedeemableNumberofShares"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AssetAcquisitionEquityInterestRedeemedorRedeemableNumberofShares" xlink:to="lab_good_AssetAcquisitionEquityInterestRedeemedorRedeemableNumberofShares" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LetterOfCreditMember_6c3054a8-4943-40ee-95e2-a1b07d01b213_terseLabel_en-US" xlink:label="lab_us-gaap_LetterOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Letter of credit </link:label>

<link:label id="lab_us-gaap_LetterOfCreditMember_label_en-US" xlink:label="lab_us-gaap_LetterOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Letter of Credit [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LetterOfCreditMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LetterOfCreditMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LetterOfCreditMember" xlink:to="lab_us-gaap_LetterOfCreditMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_AkronOhioOfficeAndLaboratoryBuildingMember_cb6df01c-6076-4953-9fcc-87252bf41b74_terseLabel_en-US" xlink:label="lab_good_AkronOhioOfficeAndLaboratoryBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Akron, Ohio Office Building </link:label>

<link:label id="lab_good_AkronOhioOfficeAndLaboratoryBuildingMember_label_en-US" xlink:label="lab_good_AkronOhioOfficeAndLaboratoryBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Akron Ohio Office And Laboratory Building [Member] </link:label>

<link:label id="lab_good_AkronOhioOfficeAndLaboratoryBuildingMember_documentation_en-US" xlink:label="lab_good_AkronOhioOfficeAndLaboratoryBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Akron Ohio office and laboratory building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AkronOhioOfficeAndLaboratoryBuildingMember" xlink:href="good-20221231.xsd#good_AkronOhioOfficeAndLaboratoryBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AkronOhioOfficeAndLaboratoryBuildingMember" xlink:to="lab_good_AkronOhioOfficeAndLaboratoryBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_srt_RangeAxis_e91df933-4b2c-48c2-9684-0939ab49b145_terseLabel_en-US" xlink:label="lab_srt_RangeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statistical Measurement [Axis] </link:label>

<link:label id="lab_srt_RangeAxis_label_en-US" xlink:label="lab_srt_RangeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statistical Measurement [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RangeAxis" xlink:to="lab_srt_RangeAxis" xlink:type="arc" order="1"/>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationDateAcquired1_c5881e27-c224-488f-b196-e196007d9465_terseLabel_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationDateAcquired1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Date acquired </link:label>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationDateAcquired1_label_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationDateAcquired1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Date Acquired </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationDateAcquired1" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RealEstateAndAccumulatedDepreciationDateAcquired1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationDateAcquired1" xlink:to="lab_srt_RealEstateAndAccumulatedDepreciationDateAcquired1" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RelatedPartyTransactionAxis_66f41fb5-9e39-4064-8fee-2795b4af305c_terseLabel_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Related Party Transaction [Axis] </link:label>

<link:label id="lab_us-gaap_RelatedPartyTransactionAxis_label_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Related Party Transaction [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis" xlink:to="lab_us-gaap_RelatedPartyTransactionAxis" xlink:type="arc" order="1"/>

<link:label id="lab_good_DividendDeclaredPeriodOneMember_ffa78835-78a7-4cfb-b0f2-e986f6462c21_terseLabel_en-US" xlink:label="lab_good_DividendDeclaredPeriodOneMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividend Declared, Period One </link:label>

<link:label id="lab_good_DividendDeclaredPeriodOneMember_label_en-US" xlink:label="lab_good_DividendDeclaredPeriodOneMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividend Declared, Period One [Member] </link:label>

<link:label id="lab_good_DividendDeclaredPeriodOneMember_documentation_en-US" xlink:label="lab_good_DividendDeclaredPeriodOneMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividend Declared, Period One [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DividendDeclaredPeriodOneMember" xlink:href="good-20221231.xsd#good_DividendDeclaredPeriodOneMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DividendDeclaredPeriodOneMember" xlink:to="lab_good_DividendDeclaredPeriodOneMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_WilkesboroNorthCarolinaMember_b2b60fed-6528-43bc-8840-839b5efb7da3_terseLabel_en-US" xlink:label="lab_good_WilkesboroNorthCarolinaMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilkesboro, North Carolina </link:label>

<link:label id="lab_good_WilkesboroNorthCarolinaMember_label_en-US" xlink:label="lab_good_WilkesboroNorthCarolinaMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilkesboro, North Carolina [Member] </link:label>

<link:label id="lab_good_WilkesboroNorthCarolinaMember_documentation_en-US" xlink:label="lab_good_WilkesboroNorthCarolinaMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilkesboro, North Carolina </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_WilkesboroNorthCarolinaMember" xlink:href="good-20221231.xsd#good_WilkesboroNorthCarolinaMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_WilkesboroNorthCarolinaMember" xlink:to="lab_good_WilkesboroNorthCarolinaMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StatementEquityComponentsAxis_c11b2f62-91b2-45c1-974c-5e010d3cd884_terseLabel_en-US" xlink:label="lab_us-gaap_StatementEquityComponentsAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equity Components [Axis] </link:label>

<link:label id="lab_us-gaap_StatementEquityComponentsAxis_label_en-US" xlink:label="lab_us-gaap_StatementEquityComponentsAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equity Components [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementEquityComponentsAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementEquityComponentsAxis" xlink:to="lab_us-gaap_StatementEquityComponentsAxis" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DividendsPayableTable_58fad7c4-d07c-4bed-8f60-b7cb7149e7ff_terseLabel_en-US" xlink:label="lab_us-gaap_DividendsPayableTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividends Payable [Table] </link:label>

<link:label id="lab_us-gaap_DividendsPayableTable_label_en-US" xlink:label="lab_us-gaap_DividendsPayableTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividends Payable [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableTable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DividendsPayableTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DividendsPayableTable" xlink:to="lab_us-gaap_DividendsPayableTable" xlink:type="arc" order="1"/>

<link:label id="lab_good_EscrowedFundsPolicyPolicyTextBlock_b14f19fd-1388-4758-b1c7-3c6fffe6f0e3_terseLabel_en-US" xlink:label="lab_good_EscrowedFundsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Funds Held in Escrow </link:label>

<link:label id="lab_good_EscrowedFundsPolicyPolicyTextBlock_label_en-US" xlink:label="lab_good_EscrowedFundsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Escrowed Funds Policy [Policy Text Block] </link:label>

<link:label id="lab_good_EscrowedFundsPolicyPolicyTextBlock_documentation_en-US" xlink:label="lab_good_EscrowedFundsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Escrowed funds. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_EscrowedFundsPolicyPolicyTextBlock" xlink:href="good-20221231.xsd#good_EscrowedFundsPolicyPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_EscrowedFundsPolicyPolicyTextBlock" xlink:to="lab_good_EscrowedFundsPolicyPolicyTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SegmentReportingPolicyPolicyTextBlock_b2d356b0-e36f-4af3-b61c-71ad527a8d93_terseLabel_en-US" xlink:label="lab_us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Segment Reporting </link:label>

<link:label id="lab_us-gaap_SegmentReportingPolicyPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Segment Reporting, Policy [Policy Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentReportingPolicyPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:to="lab_us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock_e68507f3-5317-4e0f-99e7-3d83bf2c3720_terseLabel_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Comprehensive Income </link:label>

<link:label id="lab_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Comprehensive Income, Policy [Policy Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ComprehensiveIncomePolicyPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock" xlink:to="lab_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_FortPayneAlabamaTwoIndustrialBuildingMember_403dc2ea-f59d-40a6-be8a-e4cbf19d1301_terseLabel_en-US" xlink:label="lab_good_FortPayneAlabamaTwoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fort Payne, Alabama Two Industrial Building </link:label>

<link:label id="lab_good_FortPayneAlabamaTwoIndustrialBuildingMember_label_en-US" xlink:label="lab_good_FortPayneAlabamaTwoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fort Payne, Alabama Two Industrial Building [Member] </link:label>

<link:label id="lab_good_FortPayneAlabamaTwoIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_FortPayneAlabamaTwoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fort Payne, Alabama Two Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_FortPayneAlabamaTwoIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_FortPayneAlabamaTwoIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_FortPayneAlabamaTwoIndustrialBuildingMember" xlink:to="lab_good_FortPayneAlabamaTwoIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_VariableRateTermLoanFacilityBMember_a6708b34-40fd-4c2c-a3ba-4d11c1e30025_terseLabel_en-US" xlink:label="lab_good_VariableRateTermLoanFacilityBMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate Term Loan Facility B </link:label>

<link:label id="lab_good_VariableRateTermLoanFacilityBMember_label_en-US" xlink:label="lab_good_VariableRateTermLoanFacilityBMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate Term Loan Facility B [Member] </link:label>

<link:label id="lab_good_VariableRateTermLoanFacilityBMember_documentation_en-US" xlink:label="lab_good_VariableRateTermLoanFacilityBMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate Term Loan Facility B </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_VariableRateTermLoanFacilityBMember" xlink:href="good-20221231.xsd#good_VariableRateTermLoanFacilityBMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_VariableRateTermLoanFacilityBMember" xlink:to="lab_good_VariableRateTermLoanFacilityBMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StatementLineItems_bf20038d-7a2b-4036-b236-9dd446f07b45_terseLabel_en-US" xlink:label="lab_us-gaap_StatementLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement [Line Items] </link:label>

<link:label id="lab_us-gaap_StatementLineItems_label_en-US" xlink:label="lab_us-gaap_StatementLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementLineItems" xlink:to="lab_us-gaap_StatementLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NonoperatingIncomeExpense_3d5b1d67-10e9-4270-9111-c6bb34ce710d_totalLabel_en-US" xlink:label="lab_us-gaap_NonoperatingIncomeExpense" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total other income (expense), net </link:label>

<link:label id="lab_us-gaap_NonoperatingIncomeExpense_label_en-US" xlink:label="lab_us-gaap_NonoperatingIncomeExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Nonoperating Income (Expense) </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NonoperatingIncomeExpense"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NonoperatingIncomeExpense" xlink:to="lab_us-gaap_NonoperatingIncomeExpense" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_VariableRateDomain_7dd370f8-a40b-4ed9-bf55-d1eeb51b08ee_terseLabel_en-US" xlink:label="lab_us-gaap_VariableRateDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate [Domain] </link:label>

<link:label id="lab_us-gaap_VariableRateDomain_label_en-US" xlink:label="lab_us-gaap_VariableRateDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_VariableRateDomain" xlink:to="lab_us-gaap_VariableRateDomain" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsGross_ee650700-0428-4c7c-9545-003489507519_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-lived intangible assets, gross </link:label>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsGross_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets, Gross </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberOfLongTermMortgagesIssued_99d1489e-dc8b-4871-8f5f-0784629a6d45_terseLabel_en-US" xlink:label="lab_good_NumberOfLongTermMortgagesIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of long-term mortgages issued </link:label>

<link:label id="lab_good_NumberOfLongTermMortgagesIssued_label_en-US" xlink:label="lab_good_NumberOfLongTermMortgagesIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Long Term Mortgages Issued </link:label>

<link:label id="lab_good_NumberOfLongTermMortgagesIssued_documentation_en-US" xlink:label="lab_good_NumberOfLongTermMortgagesIssued" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of long term mortgages issued. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberOfLongTermMortgagesIssued" xlink:href="good-20221231.xsd#good_NumberOfLongTermMortgagesIssued"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberOfLongTermMortgagesIssued" xlink:to="lab_good_NumberOfLongTermMortgagesIssued" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OperatingLeaseRightOfUseAsset_c918f3a0-afba-4dd4-8a57-aa48a1210d9f_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseRightOfUseAsset" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Right-of-use assets from operating leases </link:label>

<link:label id="lab_us-gaap_OperatingLeaseRightOfUseAsset_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseRightOfUseAsset" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Lease, Right-of-Use Asset </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseRightOfUseAsset" xlink:to="lab_us-gaap_OperatingLeaseRightOfUseAsset" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeMember_6c818842-58eb-48e1-b119-e5ea2122eb71_terseLabel_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> AOCI Attributable to Parent </link:label>

<link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeMember_label_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> AOCI Attributable to Parent [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:to="lab_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_AuditorFirmId_8c0de43a-4c04-4e64-9fb1-e0e50d47909c_terseLabel_en-US" xlink:label="lab_dei_AuditorFirmId" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Auditor Firm ID </link:label>

<link:label id="lab_dei_AuditorFirmId_label_en-US" xlink:label="lab_dei_AuditorFirmId" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Auditor Firm ID </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_AuditorFirmId" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_AuditorFirmId"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_AuditorFirmId" xlink:to="lab_dei_AuditorFirmId" xlink:type="arc" order="1"/>

<link:label id="lab_good_SaleOfStockGrossConsiderationReceivedOnTransaction_95cf6ec6-a9c4-4696-a845-a4365f726c7b_terseLabel_en-US" xlink:label="lab_good_SaleOfStockGrossConsiderationReceivedOnTransaction" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gross proceeds from sale of stock </link:label>

<link:label id="lab_good_SaleOfStockGrossConsiderationReceivedOnTransaction_label_en-US" xlink:label="lab_good_SaleOfStockGrossConsiderationReceivedOnTransaction" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale Of Stock, Gross Consideration Received On Transaction </link:label>

<link:label id="lab_good_SaleOfStockGrossConsiderationReceivedOnTransaction_documentation_en-US" xlink:label="lab_good_SaleOfStockGrossConsiderationReceivedOnTransaction" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale Of Stock, Gross Consideration Received On Transaction </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SaleOfStockGrossConsiderationReceivedOnTransaction" xlink:href="good-20221231.xsd#good_SaleOfStockGrossConsiderationReceivedOnTransaction"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SaleOfStockGrossConsiderationReceivedOnTransaction" xlink:to="lab_good_SaleOfStockGrossConsiderationReceivedOnTransaction" xlink:type="arc" order="1"/>

<link:label id="lab_dei_DocumentTransitionReport_7870a722-f915-40af-8abd-f86756f78e1a_terseLabel_en-US" xlink:label="lab_dei_DocumentTransitionReport" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Transition Report </link:label>

<link:label id="lab_dei_DocumentTransitionReport_label_en-US" xlink:label="lab_dei_DocumentTransitionReport" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Transition Report </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentTransitionReport"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentTransitionReport" xlink:to="lab_dei_DocumentTransitionReport" xlink:type="arc" order="1"/>

<link:label id="lab_dei_LocalPhoneNumber_4db3d1f7-6a02-4381-b430-42d5ec33e03f_terseLabel_en-US" xlink:label="lab_dei_LocalPhoneNumber" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Local Phone Number </link:label>

<link:label id="lab_dei_LocalPhoneNumber_label_en-US" xlink:label="lab_dei_LocalPhoneNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Local Phone Number </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_LocalPhoneNumber"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_LocalPhoneNumber" xlink:to="lab_dei_LocalPhoneNumber" xlink:type="arc" order="1"/>

<link:label id="lab_good_TucsonArizonaIndustrialBuildingMember_573c80f2-5d7b-4499-ba37-c46a17d28bab_terseLabel_en-US" xlink:label="lab_good_TucsonArizonaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tucson, Arizona Industrial Building </link:label>

<link:label id="lab_good_TucsonArizonaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_TucsonArizonaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tucson, Arizona Industrial Building [Member] </link:label>

<link:label id="lab_good_TucsonArizonaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_TucsonArizonaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tucson, Arizona Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_TucsonArizonaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_TucsonArizonaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_TucsonArizonaIndustrialBuildingMember" xlink:to="lab_good_TucsonArizonaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_3a1ee545-5a16-44d2-ae3e-8aa46f56d126_terseLabel_en-US" xlink:label="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Recently Issued Accounting Pronouncements </link:label>

<link:label id="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Accounting Pronouncements, Policy [Policy Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:to="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_CrossvilleTennesseeMember_aa120fe5-867d-4dcb-af68-417803be9140_terseLabel_en-US" xlink:label="lab_good_CrossvilleTennesseeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Crossville, Tennessee </link:label>

<link:label id="lab_good_CrossvilleTennesseeMember_label_en-US" xlink:label="lab_good_CrossvilleTennesseeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Crossville, Tennessee [Member] </link:label>

<link:label id="lab_good_CrossvilleTennesseeMember_documentation_en-US" xlink:label="lab_good_CrossvilleTennesseeMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Crossville, Tennessee </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CrossvilleTennesseeMember" xlink:href="good-20221231.xsd#good_CrossvilleTennesseeMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CrossvilleTennesseeMember" xlink:to="lab_good_CrossvilleTennesseeMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfRealEstatePropertiesTable_3b993ef6-0b82-475e-a578-101bc5f01bd2_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfRealEstatePropertiesTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Real Estate Properties [Table] </link:label>

<link:label id="lab_us-gaap_ScheduleOfRealEstatePropertiesTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfRealEstatePropertiesTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Real Estate Properties [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRealEstatePropertiesTable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfRealEstatePropertiesTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfRealEstatePropertiesTable" xlink:to="lab_us-gaap_ScheduleOfRealEstatePropertiesTable" xlink:type="arc" order="1"/>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_4ed6cd4d-fa83-46ca-add6-9239a908f15c_terseLabel_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Name of Property [Domain] </link:label>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_label_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Name of Property [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain" xlink:to="lab_srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_19b9cd8f-5a96-428b-9fad-0d91f01d7a05_terseLabel_en-US" xlink:label="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Adjustments to reconcile net income to net cash provided by operating activities: </link:label>

<link:label id="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_label_en-US" xlink:label="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_SaltLakeCityOfficeBuildingMember_74cf41b3-a69f-439e-b23b-ed5dbe6a311b_terseLabel_en-US" xlink:label="lab_good_SaltLakeCityOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Salt Lake City Office Building </link:label>

<link:label id="lab_good_SaltLakeCityOfficeBuildingMember_label_en-US" xlink:label="lab_good_SaltLakeCityOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Salt Lake City Office Building [Member] </link:label>

<link:label id="lab_good_SaltLakeCityOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_SaltLakeCityOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Salt Lake City Office Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SaltLakeCityOfficeBuildingMember" xlink:href="good-20221231.xsd#good_SaltLakeCityOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SaltLakeCityOfficeBuildingMember" xlink:to="lab_good_SaltLakeCityOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_93229f9a-9b77-4b9d-a29c-9f2e0b0ef163_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2026 </link:label>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, to be Paid, Year Four </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_IncomeStatementAbstract_aa0157c7-e71e-4590-8dd1-b3bcfa14c53c_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeStatementAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Statement [Abstract] </link:label>

<link:label id="lab_us-gaap_IncomeStatementAbstract_label_en-US" xlink:label="lab_us-gaap_IncomeStatementAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Statement [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeStatementAbstract" xlink:to="lab_us-gaap_IncomeStatementAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_76db2bdc-9ca5-4136-8f8b-596927be6938_terseLabel_en-US" xlink:label="lab_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Impairment charge </link:label>

<link:label id="lab_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_label_en-US" xlink:label="lab_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Impairment, Long-Lived Asset, Held-for-Use </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ImpairmentOfLongLivedAssetsHeldForUse"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:to="lab_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AdditionalPaidInCapitalMember_a0ef9852-184e-4030-832e-1923245c44f3_terseLabel_en-US" xlink:label="lab_us-gaap_AdditionalPaidInCapitalMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Additional Paid in Capital </link:label>

<link:label id="lab_us-gaap_AdditionalPaidInCapitalMember_label_en-US" xlink:label="lab_us-gaap_AdditionalPaidInCapitalMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Additional Paid-in Capital [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdditionalPaidInCapitalMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AdditionalPaidInCapitalMember" xlink:to="lab_us-gaap_AdditionalPaidInCapitalMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_DocumentFiscalPeriodFocus_b527cfcc-87fe-49c0-a35c-60130b020e25_terseLabel_en-US" xlink:label="lab_dei_DocumentFiscalPeriodFocus" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Fiscal Period Focus </link:label>

<link:label id="lab_dei_DocumentFiscalPeriodFocus_label_en-US" xlink:label="lab_dei_DocumentFiscalPeriodFocus" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Fiscal Period Focus </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentFiscalPeriodFocus"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentFiscalPeriodFocus" xlink:to="lab_dei_DocumentFiscalPeriodFocus" xlink:type="arc" order="1"/>

<link:label id="lab_good_FindlayOhioMember_f8981d96-cfc6-466f-b379-e1419fe65717_terseLabel_en-US" xlink:label="lab_good_FindlayOhioMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Findlay, Ohio </link:label>

<link:label id="lab_good_FindlayOhioMember_label_en-US" xlink:label="lab_good_FindlayOhioMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Findlay, Ohio [Member] </link:label>

<link:label id="lab_good_FindlayOhioMember_documentation_en-US" xlink:label="lab_good_FindlayOhioMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Findlay, Ohio </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_FindlayOhioMember" xlink:href="good-20221231.xsd#good_FindlayOhioMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_FindlayOhioMember" xlink:to="lab_good_FindlayOhioMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_EarningsPerShareBasicAbstract_6e6899ad-56b5-471a-8260-98a1eee822ad_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareBasicAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Calculation of basic (loss) earnings per share of common stock: </link:label>

<link:label id="lab_us-gaap_EarningsPerShareBasicAbstract_label_en-US" xlink:label="lab_us-gaap_EarningsPerShareBasicAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings Per Share, Basic [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasicAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerShareBasicAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract" xlink:to="lab_us-gaap_EarningsPerShareBasicAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_OrganizationAndSignificantAccountingPoliciesLineItems_2440c443-d713-46d6-962e-b683e3bfea32_terseLabel_en-US" xlink:label="lab_good_OrganizationAndSignificantAccountingPoliciesLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Organization And Significant Accounting Policies [Line Items] </link:label>

<link:label id="lab_good_OrganizationAndSignificantAccountingPoliciesLineItems_label_en-US" xlink:label="lab_good_OrganizationAndSignificantAccountingPoliciesLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Organization And Significant Accounting Policies [Line Items] </link:label>

<link:label id="lab_good_OrganizationAndSignificantAccountingPoliciesLineItems_documentation_en-US" xlink:label="lab_good_OrganizationAndSignificantAccountingPoliciesLineItems" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Organization and significant accounting policies. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_OrganizationAndSignificantAccountingPoliciesLineItems" xlink:href="good-20221231.xsd#good_OrganizationAndSignificantAccountingPoliciesLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_OrganizationAndSignificantAccountingPoliciesLineItems" xlink:to="lab_good_OrganizationAndSignificantAccountingPoliciesLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_good_WilkesboroNorthCarolinaIndustrialBuildingMember_a09e8ddb-794b-4c6f-ae7f-5a9e6ab512ed_terseLabel_en-US" xlink:label="lab_good_WilkesboroNorthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilkesboro, North Carolina Industrial Building </link:label>

<link:label id="lab_good_WilkesboroNorthCarolinaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_WilkesboroNorthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilkesboro, North Carolina Industrial Building [Member] </link:label>

<link:label id="lab_good_WilkesboroNorthCarolinaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_WilkesboroNorthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilkesboro, North Carolina Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_WilkesboroNorthCarolinaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_WilkesboroNorthCarolinaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_WilkesboroNorthCarolinaIndustrialBuildingMember" xlink:to="lab_good_WilkesboroNorthCarolinaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_CiceroNewYorkIndustrialBuildingMember_5057c0eb-3823-4dc2-a865-275e74335cfe_terseLabel_en-US" xlink:label="lab_good_CiceroNewYorkIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cicero, New York Industrial Building </link:label>

<link:label id="lab_good_CiceroNewYorkIndustrialBuildingMember_label_en-US" xlink:label="lab_good_CiceroNewYorkIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cicero New York Industrial Building [Member] </link:label>

<link:label id="lab_good_CiceroNewYorkIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_CiceroNewYorkIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cicero New York industrial building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CiceroNewYorkIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_CiceroNewYorkIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CiceroNewYorkIndustrialBuildingMember" xlink:to="lab_good_CiceroNewYorkIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy_3ebd04ef-76a2-472a-b36b-6d2b3b4f5973_terseLabel_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash and Cash Equivalents </link:label>

<link:label id="lab_us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy_label_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash and Cash Equivalents, Unrestricted Cash and Cash Equivalents, Policy [Policy Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy" xlink:to="lab_us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_f048b87d-5c6b-464c-a095-1f81e9f33a33_terseLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Diluted (in shares) </link:label>

<link:label id="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_164fcc7a-fe3c-4c66-bc9f-d61e0cdd9fcc_totalLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Denominator for diluted weighted average shares of common stock (in shares) </link:label>

<link:label id="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_label_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Number of Shares Outstanding, Diluted </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements_575955ee-5f69-4ab2-bd34-5943f448a596_verboseLabel_en-US" xlink:label="lab_us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Buildings & improvements, total cost </link:label>

<link:label id="lab_us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements_label_en-US" xlink:label="lab_us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements" xlink:to="lab_us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet_a7511fb5-ef05-4418-8ec0-ca1b73af5fd8_totalLabel_en-US" xlink:label="lab_us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total derivative liabilities, net </link:label>

<link:label id="lab_us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet_label_en-US" xlink:label="lab_us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Assets (Liabilities), at Fair Value, Net </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet" xlink:to="lab_us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet" xlink:type="arc" order="1"/>

<link:label id="lab_good_EarningsPerWeightedAverageShareOfSeniorCommonStock_c7503b13-fcbf-4af6-a8f2-2ae4ff9b4cee_terseLabel_en-US" xlink:label="lab_good_EarningsPerWeightedAverageShareOfSeniorCommonStock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings per weighted average share of senior common stock (in dollars per share) </link:label>

<link:label id="lab_good_EarningsPerWeightedAverageShareOfSeniorCommonStock_label_en-US" xlink:label="lab_good_EarningsPerWeightedAverageShareOfSeniorCommonStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings Per Weighted Average Share Of Senior Common Stock </link:label>

<link:label id="lab_good_EarningsPerWeightedAverageShareOfSeniorCommonStock_documentation_en-US" xlink:label="lab_good_EarningsPerWeightedAverageShareOfSeniorCommonStock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings per weighted average share of senior common stock. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_EarningsPerWeightedAverageShareOfSeniorCommonStock" xlink:href="good-20221231.xsd#good_EarningsPerWeightedAverageShareOfSeniorCommonStock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_EarningsPerWeightedAverageShareOfSeniorCommonStock" xlink:to="lab_good_EarningsPerWeightedAverageShareOfSeniorCommonStock" xlink:type="arc" order="1"/>

<link:label id="lab_good_ScheduleOfComponentsOfIncomeFromRealEstateAndRelatedAssetsDispositionsTableTextBlock_e48a060c-858d-4589-8cf8-393c4ba8d7b8_terseLabel_en-US" xlink:label="lab_good_ScheduleOfComponentsOfIncomeFromRealEstateAndRelatedAssetsDispositionsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Components of Operating Income from Real Estate and Related Assets Disposed </link:label>

<link:label id="lab_good_ScheduleOfComponentsOfIncomeFromRealEstateAndRelatedAssetsDispositionsTableTextBlock_label_en-US" xlink:label="lab_good_ScheduleOfComponentsOfIncomeFromRealEstateAndRelatedAssetsDispositionsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Components of Income From Real Estate and Related Assets Dispositions [Table Text Block] </link:label>

<link:label id="lab_good_ScheduleOfComponentsOfIncomeFromRealEstateAndRelatedAssetsDispositionsTableTextBlock_documentation_en-US" xlink:label="lab_good_ScheduleOfComponentsOfIncomeFromRealEstateAndRelatedAssetsDispositionsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Components of Income From Real Estate and Related Assets Dispositions [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ScheduleOfComponentsOfIncomeFromRealEstateAndRelatedAssetsDispositionsTableTextBlock" xlink:href="good-20221231.xsd#good_ScheduleOfComponentsOfIncomeFromRealEstateAndRelatedAssetsDispositionsTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ScheduleOfComponentsOfIncomeFromRealEstateAndRelatedAssetsDispositionsTableTextBlock" xlink:to="lab_good_ScheduleOfComponentsOfIncomeFromRealEstateAndRelatedAssetsDispositionsTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_DebtInstrumentExtensionPeriod_871bcb80-e79e-40c6-9a7a-33b9193c3b22_terseLabel_en-US" xlink:label="lab_good_DebtInstrumentExtensionPeriod" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Extension Term </link:label>

<link:label id="lab_good_DebtInstrumentExtensionPeriod_label_en-US" xlink:label="lab_good_DebtInstrumentExtensionPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Extension Period </link:label>

<link:label id="lab_good_DebtInstrumentExtensionPeriod_documentation_en-US" xlink:label="lab_good_DebtInstrumentExtensionPeriod" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Extension Period </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DebtInstrumentExtensionPeriod" xlink:href="good-20221231.xsd#good_DebtInstrumentExtensionPeriod"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DebtInstrumentExtensionPeriod" xlink:to="lab_good_DebtInstrumentExtensionPeriod" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstatePropertiesAxis_01c13912-c99a-4e39-b28c-2f68fbd2eaf8_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstatePropertiesAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Property Ownership [Axis] </link:label>

<link:label id="lab_us-gaap_RealEstatePropertiesAxis_label_en-US" xlink:label="lab_us-gaap_RealEstatePropertiesAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Property Ownership [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstatePropertiesAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstatePropertiesAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstatePropertiesAxis" xlink:to="lab_us-gaap_RealEstatePropertiesAxis" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_BuildingAndBuildingImprovementsMember_9f68fe5a-95d1-41fd-a19e-5f75456db71c_terseLabel_en-US" xlink:label="lab_us-gaap_BuildingAndBuildingImprovementsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Building and Improvements </link:label>

<link:label id="lab_us-gaap_BuildingAndBuildingImprovementsMember_label_en-US" xlink:label="lab_us-gaap_BuildingAndBuildingImprovementsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Building and Building Improvements [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingAndBuildingImprovementsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BuildingAndBuildingImprovementsMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BuildingAndBuildingImprovementsMember" xlink:to="lab_us-gaap_BuildingAndBuildingImprovementsMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CommonStockDividendsPerShareCashPaid_8214267c-0a9b-4bdc-b339-4d8db9cbd717_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockDividendsPerShareCashPaid" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common stock, cash paid (in dollars per share) </link:label>

<link:label id="lab_us-gaap_CommonStockDividendsPerShareCashPaid_label_en-US" xlink:label="lab_us-gaap_CommonStockDividendsPerShareCashPaid" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock, Dividends, Per Share, Cash Paid </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareCashPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockDividendsPerShareCashPaid"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockDividendsPerShareCashPaid" xlink:to="lab_us-gaap_CommonStockDividendsPerShareCashPaid" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NumberOfPropertiesSubjectToGroundLeases_49c0d3d6-9cbc-4c05-9970-0dfee2ae2ee3_terseLabel_en-US" xlink:label="lab_us-gaap_NumberOfPropertiesSubjectToGroundLeases" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of leases </link:label>

<link:label id="lab_us-gaap_NumberOfPropertiesSubjectToGroundLeases_label_en-US" xlink:label="lab_us-gaap_NumberOfPropertiesSubjectToGroundLeases" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Properties Subject to Ground Leases </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfPropertiesSubjectToGroundLeases" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NumberOfPropertiesSubjectToGroundLeases"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NumberOfPropertiesSubjectToGroundLeases" xlink:to="lab_us-gaap_NumberOfPropertiesSubjectToGroundLeases" xlink:type="arc" order="1"/>

<link:label id="lab_dei_IcfrAuditorAttestationFlag_0986b7b2-978b-486a-95d2-a5918bb9b39f_terseLabel_en-US" xlink:label="lab_dei_IcfrAuditorAttestationFlag" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> ICFR Auditor Attestation Flag </link:label>

<link:label id="lab_dei_IcfrAuditorAttestationFlag_label_en-US" xlink:label="lab_dei_IcfrAuditorAttestationFlag" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> ICFR Auditor Attestation Flag </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_IcfrAuditorAttestationFlag" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_IcfrAuditorAttestationFlag"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_IcfrAuditorAttestationFlag" xlink:to="lab_dei_IcfrAuditorAttestationFlag" xlink:type="arc" order="1"/>

<link:label id="lab_good_RealEstateCostsAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements_37df988b-7e21-4aa5-86ef-cbea99b724b7_terseLabel_en-US" xlink:label="lab_good_RealEstateCostsAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Improvement costs capitalized subsequent to acquisition </link:label>

<link:label id="lab_good_RealEstateCostsAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements_label_en-US" xlink:label="lab_good_RealEstateCostsAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Costs and Accumulated Depreciation Costs Capitalized Subsequent to Acquisition Improvements </link:label>

<link:label id="lab_good_RealEstateCostsAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements_documentation_en-US" xlink:label="lab_good_RealEstateCostsAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Costs and Accumulated Depreciation Costs Capitalized Subsequent to Acquisition Improvements </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_RealEstateCostsAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements" xlink:href="good-20221231.xsd#good_RealEstateCostsAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_RealEstateCostsAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements" xlink:to="lab_good_RealEstateCostsAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements" xlink:type="arc" order="1"/>

<link:label id="lab_good_ParsippanyNewJerseyMember_e9f6279e-0cbb-4203-9a3a-c3505270b088_terseLabel_en-US" xlink:label="lab_good_ParsippanyNewJerseyMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Parsippany, New Jersey </link:label>

<link:label id="lab_good_ParsippanyNewJerseyMember_label_en-US" xlink:label="lab_good_ParsippanyNewJerseyMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Parsippany, New Jersey [Member] </link:label>

<link:label id="lab_good_ParsippanyNewJerseyMember_documentation_en-US" xlink:label="lab_good_ParsippanyNewJerseyMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Parsippany, New Jersey </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ParsippanyNewJerseyMember" xlink:href="good-20221231.xsd#good_ParsippanyNewJerseyMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ParsippanyNewJerseyMember" xlink:to="lab_good_ParsippanyNewJerseyMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_MenomoneeFallsWisconsinIndustrialBuildingMember_4a007931-0b42-4872-8925-5accd44a0041_terseLabel_en-US" xlink:label="lab_good_MenomoneeFallsWisconsinIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Menomonee Falls, Wisconsin Industrial Building </link:label>

<link:label id="lab_good_MenomoneeFallsWisconsinIndustrialBuildingMember_label_en-US" xlink:label="lab_good_MenomoneeFallsWisconsinIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Menomonee Falls Wisconsin Industrial Building [Member] </link:label>

<link:label id="lab_good_MenomoneeFallsWisconsinIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_MenomoneeFallsWisconsinIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Menomonee Falls Wisconsin industrial building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_MenomoneeFallsWisconsinIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_MenomoneeFallsWisconsinIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_MenomoneeFallsWisconsinIndustrialBuildingMember" xlink:to="lab_good_MenomoneeFallsWisconsinIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_GreenvilleSouthCarolinaMember_f69fa71a-1875-4b95-9ee1-caf743f88bc8_terseLabel_en-US" xlink:label="lab_good_GreenvilleSouthCarolinaMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Greenville, South Carolina </link:label>

<link:label id="lab_good_GreenvilleSouthCarolinaMember_label_en-US" xlink:label="lab_good_GreenvilleSouthCarolinaMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Greenville, South Carolina [Member] </link:label>

<link:label id="lab_good_GreenvilleSouthCarolinaMember_documentation_en-US" xlink:label="lab_good_GreenvilleSouthCarolinaMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Greenville, South Carolina </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_GreenvilleSouthCarolinaMember" xlink:href="good-20221231.xsd#good_GreenvilleSouthCarolinaMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_GreenvilleSouthCarolinaMember" xlink:to="lab_good_GreenvilleSouthCarolinaMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_GrandRapidsMichiganOfficeBuildingMember_84d57b4f-aad8-4da4-bfd5-f634251e7dc4_terseLabel_en-US" xlink:label="lab_good_GrandRapidsMichiganOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Grand Rapids, Michigan Office Building </link:label>

<link:label id="lab_good_GrandRapidsMichiganOfficeBuildingMember_label_en-US" xlink:label="lab_good_GrandRapidsMichiganOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Grand Rapids Michigan Office Building [Member] </link:label>

<link:label id="lab_good_GrandRapidsMichiganOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_GrandRapidsMichiganOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Grand Rapids Michigan office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_GrandRapidsMichiganOfficeBuildingMember" xlink:href="good-20221231.xsd#good_GrandRapidsMichiganOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_GrandRapidsMichiganOfficeBuildingMember" xlink:to="lab_good_GrandRapidsMichiganOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PreferredStockSharesAuthorized_98de590e-7f9c-49e2-9dc9-a4af77cca484_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Redeemable preferred stock, shares authorized (in shares) </link:label>

<link:label id="lab_us-gaap_PreferredStockSharesAuthorized_label_en-US" xlink:label="lab_us-gaap_PreferredStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred Stock, Shares Authorized </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockSharesAuthorized"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockSharesAuthorized" xlink:to="lab_us-gaap_PreferredStockSharesAuthorized" xlink:type="arc" order="1"/>

<link:label id="lab_good_SeniorCommonStockSharesAuthorized_c02c69f3-a7e4-418b-b11a-23dace839cb9_terseLabel_en-US" xlink:label="lab_good_SeniorCommonStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior common stock, shares authorized (in shares) </link:label>

<link:label id="lab_good_SeniorCommonStockSharesAuthorized_label_en-US" xlink:label="lab_good_SeniorCommonStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior Common Stock Shares Authorized </link:label>

<link:label id="lab_good_SeniorCommonStockSharesAuthorized_documentation_en-US" xlink:label="lab_good_SeniorCommonStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior common stock, shares authorized. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SeniorCommonStockSharesAuthorized" xlink:href="good-20221231.xsd#good_SeniorCommonStockSharesAuthorized"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SeniorCommonStockSharesAuthorized" xlink:to="lab_good_SeniorCommonStockSharesAuthorized" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_8e905402-5b3d-4b70-b2e4-757621c50bca_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net loss (income) attributable (available) to OP Units held by Non-controlling OP Unitholders </link:label>

<link:label id="lab_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_label_en-US" xlink:label="lab_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Income (Loss) Attributable to Noncontrolling Interest </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:to="lab_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_2e8b3e99-221a-4602-bcf8-00948eb9e9f1_terseLabel_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commitments and Contingencies </link:label>

<link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commitments and Contingencies Disclosure [Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:to="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_PacificMissouriIndustrialBuildingFourMember_b9aeefec-5dda-4f8e-98a7-051dcf00971e_terseLabel_en-US" xlink:label="lab_good_PacificMissouriIndustrialBuildingFourMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pacific, Missouri Industrial Building Four </link:label>

<link:label id="lab_good_PacificMissouriIndustrialBuildingFourMember_label_en-US" xlink:label="lab_good_PacificMissouriIndustrialBuildingFourMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pacific, Missouri Industrial Building Four [Member] </link:label>

<link:label id="lab_good_PacificMissouriIndustrialBuildingFourMember_documentation_en-US" xlink:label="lab_good_PacificMissouriIndustrialBuildingFourMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pacific, Missouri Industrial Building Four </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PacificMissouriIndustrialBuildingFourMember" xlink:href="good-20221231.xsd#good_PacificMissouriIndustrialBuildingFourMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PacificMissouriIndustrialBuildingFourMember" xlink:to="lab_good_PacificMissouriIndustrialBuildingFourMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ProceedsFromIssuanceOfLongTermDebt_a6fd24ff-be52-4801-a125-2fa9ba1fc035_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Borrowings on term loan </link:label>

<link:label id="lab_us-gaap_ProceedsFromIssuanceOfLongTermDebt_label_en-US" xlink:label="lab_us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from Issuance of Long-Term Debt </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:to="lab_us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_efdf5c26-d661-42a8-8c54-1cdc50f5e444_totalLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net (loss) income (attributable) available to common stockholders </link:label>

<link:label id="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_f365fc69-89f6-4f08-afa6-90b099d90407_terseLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net (loss) income (attributable) available to common stockholders </link:label>

<link:label id="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_label_en-US" xlink:label="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Income (Loss) Available to Common Stockholders, Basic </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CommonStockSharesIssued_9b4e52d8-6dda-4501-b693-5b3997d11a90_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common stock, shares issued (in shares) </link:label>

<link:label id="lab_us-gaap_CommonStockSharesIssued_label_en-US" xlink:label="lab_us-gaap_CommonStockSharesIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock, Shares, Issued </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesIssued"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockSharesIssued" xlink:to="lab_us-gaap_CommonStockSharesIssued" xlink:type="arc" order="1"/>

<link:label id="lab_good_NewFixedRateMortgageNotesPayableMember_3707589e-36c5-4201-932a-469f1e9a802f_terseLabel_en-US" xlink:label="lab_good_NewFixedRateMortgageNotesPayableMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New fixed rate mortgage notes payable </link:label>

<link:label id="lab_good_NewFixedRateMortgageNotesPayableMember_label_en-US" xlink:label="lab_good_NewFixedRateMortgageNotesPayableMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Fixed Rate Mortgage Notes Payable [Member] </link:label>

<link:label id="lab_good_NewFixedRateMortgageNotesPayableMember_documentation_en-US" xlink:label="lab_good_NewFixedRateMortgageNotesPayableMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Fixed Rate Mortgage Notes Payable [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NewFixedRateMortgageNotesPayableMember" xlink:href="good-20221231.xsd#good_NewFixedRateMortgageNotesPayableMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NewFixedRateMortgageNotesPayableMember" xlink:to="lab_good_NewFixedRateMortgageNotesPayableMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_DenverColoradoMember_e2bed81a-44ed-4df0-9102-03513fc6da5d_terseLabel_en-US" xlink:label="lab_good_DenverColoradoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Denver, Colorado </link:label>

<link:label id="lab_good_DenverColoradoMember_label_en-US" xlink:label="lab_good_DenverColoradoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Denver, Colorado [Member] </link:label>

<link:label id="lab_good_DenverColoradoMember_documentation_en-US" xlink:label="lab_good_DenverColoradoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Denver, Colorado </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DenverColoradoMember" xlink:href="good-20221231.xsd#good_DenverColoradoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DenverColoradoMember" xlink:to="lab_good_DenverColoradoMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_BelowMarketLeaseMember_2dc9a5d3-fcf1-48e7-9504-0a0e13292fff_terseLabel_en-US" xlink:label="lab_good_BelowMarketLeaseMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Below Market Leases </link:label>

<link:label id="lab_good_BelowMarketLeaseMember_label_en-US" xlink:label="lab_good_BelowMarketLeaseMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Below Market Lease [Member] </link:label>

<link:label id="lab_good_BelowMarketLeaseMember_documentation_en-US" xlink:label="lab_good_BelowMarketLeaseMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Below Market Lease [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_BelowMarketLeaseMember" xlink:href="good-20221231.xsd#good_BelowMarketLeaseMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_BelowMarketLeaseMember" xlink:to="lab_good_BelowMarketLeaseMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_SecuredMortgagesFinancingFeePercent_bafee27e-2b9f-4afd-8157-3d1ba645349d_terseLabel_en-US" xlink:label="lab_good_SecuredMortgagesFinancingFeePercent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Financing fee on total secured mortgages </link:label>

<link:label id="lab_good_SecuredMortgagesFinancingFeePercent_label_en-US" xlink:label="lab_good_SecuredMortgagesFinancingFeePercent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Secured Mortgages Financing Fee Percent </link:label>

<link:label id="lab_good_SecuredMortgagesFinancingFeePercent_documentation_en-US" xlink:label="lab_good_SecuredMortgagesFinancingFeePercent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Secured mortgages financing fee percent. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SecuredMortgagesFinancingFeePercent" xlink:href="good-20221231.xsd#good_SecuredMortgagesFinancingFeePercent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SecuredMortgagesFinancingFeePercent" xlink:to="lab_good_SecuredMortgagesFinancingFeePercent" xlink:type="arc" order="1"/>

<link:label id="lab_good_DebtInstrumentInterestRateVariableRateatPeriodEnd_a835e889-6236-4e94-b496-0f57d0439fc9_terseLabel_en-US" xlink:label="lab_good_DebtInstrumentInterestRateVariableRateatPeriodEnd" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable rate at period end </link:label>

<link:label id="lab_good_DebtInstrumentInterestRateVariableRateatPeriodEnd_label_en-US" xlink:label="lab_good_DebtInstrumentInterestRateVariableRateatPeriodEnd" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Interest Rate, Variable Rate at Period End </link:label>

<link:label id="lab_good_DebtInstrumentInterestRateVariableRateatPeriodEnd_documentation_en-US" xlink:label="lab_good_DebtInstrumentInterestRateVariableRateatPeriodEnd" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Interest Rate, Variable Rate at Period End </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DebtInstrumentInterestRateVariableRateatPeriodEnd" xlink:href="good-20221231.xsd#good_DebtInstrumentInterestRateVariableRateatPeriodEnd"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DebtInstrumentInterestRateVariableRateatPeriodEnd" xlink:to="lab_good_DebtInstrumentInterestRateVariableRateatPeriodEnd" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivities_22f670c6-a5f1-4f35-99bd-acbae13d6070_totalLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net cash used in investing activities </link:label>

<link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivities_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Cash Provided by (Used in) Investing Activities </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="lab_us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:type="arc" order="1"/>

<link:label id="lab_good_ChalfontPennsylvaniaIndustrialBuildingMember_31e405fd-6f07-4749-a258-bf23a8462620_terseLabel_en-US" xlink:label="lab_good_ChalfontPennsylvaniaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Chalfont, Pennsylvania Industrial Building </link:label>

<link:label id="lab_good_ChalfontPennsylvaniaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_ChalfontPennsylvaniaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Chalfont Pennsylvania Industrial Building [Member] </link:label>

<link:label id="lab_good_ChalfontPennsylvaniaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_ChalfontPennsylvaniaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Chalfont Pennsylvania industrial building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ChalfontPennsylvaniaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_ChalfontPennsylvaniaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ChalfontPennsylvaniaIndustrialBuildingMember" xlink:to="lab_good_ChalfontPennsylvaniaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ComprehensiveIncomeNetOfTax_e0c00b54-89ae-48a6-ae88-2406a7dc7879_totalLabel_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomeNetOfTax" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total comprehensive income available to the Company </link:label>

<link:label id="lab_us-gaap_ComprehensiveIncomeNetOfTax_label_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomeNetOfTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Comprehensive Income (Loss), Net of Tax, Attributable to Parent </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax" xlink:to="lab_us-gaap_ComprehensiveIncomeNetOfTax" xlink:type="arc" order="1"/>

<link:label id="lab_good_A6.625SeriesECumulativeRedeemablePreferredStockMember_6f8e5327-8278-4cc5-ae96-2f853b58d92c_terseLabel_en-US" xlink:label="lab_good_A6.625SeriesECumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 6.625% Series E Cumulative Redeemable Preferred Stock </link:label>

<link:label id="lab_good_A6.625SeriesECumulativeRedeemablePreferredStockMember_label_en-US" xlink:label="lab_good_A6.625SeriesECumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 6.625% Series E Cumulative Redeemable Preferred Stock [Member] </link:label>

<link:label id="lab_good_A6.625SeriesECumulativeRedeemablePreferredStockMember_documentation_en-US" xlink:label="lab_good_A6.625SeriesECumulativeRedeemablePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 6.625% Series E Cumulative Redeemable Preferred Stock [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_A6.625SeriesECumulativeRedeemablePreferredStockMember" xlink:href="good-20221231.xsd#good_A6.625SeriesECumulativeRedeemablePreferredStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_A6.625SeriesECumulativeRedeemablePreferredStockMember" xlink:to="lab_good_A6.625SeriesECumulativeRedeemablePreferredStockMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_PaymentsToTenantsFromReserves_981e7283-6844-49ad-9897-eb73a2b3ee2e_negatedLabel_en-US" xlink:label="lab_good_PaymentsToTenantsFromReserves" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments to tenants from reserves </link:label>

<link:label id="lab_good_PaymentsToTenantsFromReserves_label_en-US" xlink:label="lab_good_PaymentsToTenantsFromReserves" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments To Tenants From Reserves </link:label>

<link:label id="lab_good_PaymentsToTenantsFromReserves_documentation_en-US" xlink:label="lab_good_PaymentsToTenantsFromReserves" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments to tenants from reserves. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PaymentsToTenantsFromReserves" xlink:href="good-20221231.xsd#good_PaymentsToTenantsFromReserves"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PaymentsToTenantsFromReserves" xlink:to="lab_good_PaymentsToTenantsFromReserves" xlink:type="arc" order="1"/>

<link:label id="lab_good_GainLossOnExtinguishmentOfPreferredStock_e1ae44bf-3a94-47d9-a568-d4ff1f520493_terseLabel_en-US" xlink:label="lab_good_GainLossOnExtinguishmentOfPreferredStock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loss on extinguishment of Series F preferred stock </link:label>

<link:label id="lab_good_GainLossOnExtinguishmentOfPreferredStock_label_en-US" xlink:label="lab_good_GainLossOnExtinguishmentOfPreferredStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gain (Loss) on Extinguishment of Preferred Stock </link:label>

<link:label id="lab_good_GainLossOnExtinguishmentOfPreferredStock_documentation_en-US" xlink:label="lab_good_GainLossOnExtinguishmentOfPreferredStock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gain (Loss) on Extinguishment of Preferred Stock </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_GainLossOnExtinguishmentOfPreferredStock" xlink:href="good-20221231.xsd#good_GainLossOnExtinguishmentOfPreferredStock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_GainLossOnExtinguishmentOfPreferredStock" xlink:to="lab_good_GainLossOnExtinguishmentOfPreferredStock" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityCurrentReportingStatus_3ff23ad7-e139-449d-9eee-927a50ac2ab5_terseLabel_en-US" xlink:label="lab_dei_EntityCurrentReportingStatus" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Current Reporting Status </link:label>

<link:label id="lab_dei_EntityCurrentReportingStatus_label_en-US" xlink:label="lab_dei_EntityCurrentReportingStatus" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Current Reporting Status </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityCurrentReportingStatus"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityCurrentReportingStatus" xlink:to="lab_dei_EntityCurrentReportingStatus" xlink:type="arc" order="1"/>

<link:label id="lab_good_AuditorInformationAbstract_label_en-US" xlink:label="lab_good_AuditorInformationAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Auditor Information [Abstract] </link:label>

<link:label id="lab_good_AuditorInformationAbstract_documentation_en-US" xlink:label="lab_good_AuditorInformationAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Auditor Information </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AuditorInformationAbstract" xlink:href="good-20221231.xsd#good_AuditorInformationAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AuditorInformationAbstract" xlink:to="lab_good_AuditorInformationAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_MaitlandFloridaOfficeBuildingMember_c623134c-c57f-4ce6-a0a4-d87c2acbf410_terseLabel_en-US" xlink:label="lab_good_MaitlandFloridaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Maitland Florida Office Building </link:label>

<link:label id="lab_good_MaitlandFloridaOfficeBuildingMember_label_en-US" xlink:label="lab_good_MaitlandFloridaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Maitland Florida Office Building [Member] </link:label>

<link:label id="lab_good_MaitlandFloridaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_MaitlandFloridaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Maitland Florida Office Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_MaitlandFloridaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_MaitlandFloridaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_MaitlandFloridaOfficeBuildingMember" xlink:to="lab_good_MaitlandFloridaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_AssetRetirementObligationExpense_9a98fd8c-46ec-44bd-b581-fecae8c4ad56_terseLabel_en-US" xlink:label="lab_good_AssetRetirementObligationExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset retirement obligation expense </link:label>

<link:label id="lab_good_AssetRetirementObligationExpense_label_en-US" xlink:label="lab_good_AssetRetirementObligationExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset Retirement Obligation Expense </link:label>

<link:label id="lab_good_AssetRetirementObligationExpense_documentation_en-US" xlink:label="lab_good_AssetRetirementObligationExpense" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset retirement obligation expense. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AssetRetirementObligationExpense" xlink:href="good-20221231.xsd#good_AssetRetirementObligationExpense"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AssetRetirementObligationExpense" xlink:to="lab_good_AssetRetirementObligationExpense" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_TemporaryEquityLiquidationPreferencePerShare_b2dd145d-f19b-451d-be11-97a3147aa8ed_verboseLabel_en-US" xlink:label="lab_us-gaap_TemporaryEquityLiquidationPreferencePerShare" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Redeemable preferred stock, liquidation preference (in dollars per share) </link:label>

<link:label id="lab_us-gaap_TemporaryEquityLiquidationPreferencePerShare_label_en-US" xlink:label="lab_us-gaap_TemporaryEquityLiquidationPreferencePerShare" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Temporary Equity, Liquidation Preference Per Share </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityLiquidationPreferencePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TemporaryEquityLiquidationPreferencePerShare"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TemporaryEquityLiquidationPreferencePerShare" xlink:to="lab_us-gaap_TemporaryEquityLiquidationPreferencePerShare" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DividendsPayableAmountPerShare_18cdfbd1-9495-4050-8018-deb37c686b4a_terseLabel_en-US" xlink:label="lab_us-gaap_DividendsPayableAmountPerShare" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Distributions (in dollars per share) </link:label>

<link:label id="lab_us-gaap_DividendsPayableAmountPerShare_label_en-US" xlink:label="lab_us-gaap_DividendsPayableAmountPerShare" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividends Payable, Amount Per Share </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableAmountPerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DividendsPayableAmountPerShare"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DividendsPayableAmountPerShare" xlink:to="lab_us-gaap_DividendsPayableAmountPerShare" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_f0214b5b-9012-410e-a5f5-fbc34aa3280e_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair Value of Acquired Assets and Liabilities Assumed </link:label>

<link:label id="lab_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_MontgomeryAlabamaIndustrialBuildingMember_0922b9f4-1583-425a-b9c0-283fa4f33284_terseLabel_en-US" xlink:label="lab_good_MontgomeryAlabamaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Montgomery, Alabama Industrial Building </link:label>

<link:label id="lab_good_MontgomeryAlabamaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_MontgomeryAlabamaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Montgomery, Alabama Industrial Building [Member] </link:label>

<link:label id="lab_good_MontgomeryAlabamaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_MontgomeryAlabamaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Montgomery, Alabama Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_MontgomeryAlabamaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_MontgomeryAlabamaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_MontgomeryAlabamaIndustrialBuildingMember" xlink:to="lab_good_MontgomeryAlabamaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_ReceiptsFromLendersForReservesHeldInEscrow_64d42f8d-4174-4ed2-8d29-ce76bdcb93bb_terseLabel_en-US" xlink:label="lab_good_ReceiptsFromLendersForReservesHeldInEscrow" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Receipts from lenders for funds held in escrow </link:label>

<link:label id="lab_good_ReceiptsFromLendersForReservesHeldInEscrow_label_en-US" xlink:label="lab_good_ReceiptsFromLendersForReservesHeldInEscrow" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Receipts From Lenders For Reserves Held In Escrow </link:label>

<link:label id="lab_good_ReceiptsFromLendersForReservesHeldInEscrow_documentation_en-US" xlink:label="lab_good_ReceiptsFromLendersForReservesHeldInEscrow" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Receipts from lenders for funds held in escrow. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ReceiptsFromLendersForReservesHeldInEscrow" xlink:href="good-20221231.xsd#good_ReceiptsFromLendersForReservesHeldInEscrow"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ReceiptsFromLendersForReservesHeldInEscrow" xlink:to="lab_good_ReceiptsFromLendersForReservesHeldInEscrow" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfStockByClassTable_ba6ad312-18e9-4008-a5c3-cdf754d6446c_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfStockByClassTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Stock by Class [Table] </link:label>

<link:label id="lab_us-gaap_ScheduleOfStockByClassTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfStockByClassTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Stock by Class [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfStockByClassTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable" xlink:to="lab_us-gaap_ScheduleOfStockByClassTable" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_GainLossOnSaleOfProperties_aabf1503-53b8-4ada-b2ae-610c0d1ec2bd_terseLabel_en-US" xlink:label="lab_us-gaap_GainLossOnSaleOfProperties" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gain (loss) on sale of real estate, net </link:label>

<link:label id="lab_us-gaap_GainLossOnSaleOfProperties_c3788e93-ed66-48fd-8b9c-6c22aed3ed62_negatedLabel_en-US" xlink:label="lab_us-gaap_GainLossOnSaleOfProperties" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> (Gain) loss on sale of real estate, net </link:label>

<link:label id="lab_us-gaap_GainLossOnSaleOfProperties_51d64b98-8fcc-4dd3-84fc-189856ba8c49_verboseLabel_en-US" xlink:label="lab_us-gaap_GainLossOnSaleOfProperties" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate Gain on Sale of Real Estate, net </link:label>

<link:label id="lab_us-gaap_GainLossOnSaleOfProperties_d7413579-7fb5-4d8d-849d-f6dc24d9e9a3_netLabel_en-US" xlink:label="lab_us-gaap_GainLossOnSaleOfProperties" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loss on sale of real estate, net </link:label>

<link:label id="lab_us-gaap_GainLossOnSaleOfProperties_label_en-US" xlink:label="lab_us-gaap_GainLossOnSaleOfProperties" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gain (Loss) on Sale of Properties </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfProperties" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GainLossOnSaleOfProperties"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GainLossOnSaleOfProperties" xlink:to="lab_us-gaap_GainLossOnSaleOfProperties" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SeriesGPreferredStockMember_67c04db3-edc7-4c99-8cdd-64b1b14ea5ac_terseLabel_en-US" xlink:label="lab_us-gaap_SeriesGPreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series G Preferred Stock </link:label>

<link:label id="lab_us-gaap_SeriesGPreferredStockMember_label_en-US" xlink:label="lab_us-gaap_SeriesGPreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Series G Preferred Stock [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesGPreferredStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeriesGPreferredStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SeriesGPreferredStockMember" xlink:to="lab_us-gaap_SeriesGPreferredStockMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LiabilitiesAbstract_627de715-3f4e-4ffd-a596-3f4838f8e7e7_terseLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> LIABILITIES </link:label>

<link:label id="lab_us-gaap_LiabilitiesAbstract_label_en-US" xlink:label="lab_us-gaap_LiabilitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liabilities [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LiabilitiesAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesAbstract" xlink:to="lab_us-gaap_LiabilitiesAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntitiesTable_ee8e0768-1a8b-490a-be0c-0fe34357be4c_terseLabel_en-US" xlink:label="lab_dei_EntitiesTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entities [Table] </link:label>

<link:label id="lab_dei_EntitiesTable_label_en-US" xlink:label="lab_dei_EntitiesTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entities [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntitiesTable" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntitiesTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntitiesTable" xlink:to="lab_dei_EntitiesTable" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock_b71f9f1a-7605-4d7b-9c82-7d1a0e74670a_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Estimated Aggregate Amortization Expense </link:label>

<link:label id="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:to="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateAccumulatedDepreciation_64581c5b-e965-4648-b8b4-1fd24aef06d5_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstateAccumulatedDepreciation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accumulated depreciation </link:label>

<link:label id="lab_us-gaap_RealEstateAccumulatedDepreciation_ca677cb4-3820-437d-9e73-ab81268dda74_periodStartLabel_en-US" xlink:label="lab_us-gaap_RealEstateAccumulatedDepreciation" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Balance at beginning of period </link:label>

<link:label id="lab_us-gaap_RealEstateAccumulatedDepreciation_7bd1059c-1e10-45c0-b486-e94b1a0f57bd_periodEndLabel_en-US" xlink:label="lab_us-gaap_RealEstateAccumulatedDepreciation" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Balance at end of period </link:label>

<link:label id="lab_us-gaap_RealEstateAccumulatedDepreciation_label_en-US" xlink:label="lab_us-gaap_RealEstateAccumulatedDepreciation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateAccumulatedDepreciation" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateAccumulatedDepreciation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateAccumulatedDepreciation" xlink:to="lab_us-gaap_RealEstateAccumulatedDepreciation" xlink:type="arc" order="1"/>

<link:label id="lab_good_RealEstateAndAccumulatedDepreciationYearOfConstructionOrImprovements_7f6ea193-5470-4547-b315-afc1d174bc6a_terseLabel_en-US" xlink:label="lab_good_RealEstateAndAccumulatedDepreciationYearOfConstructionOrImprovements" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Year construction/ improvements </link:label>

<link:label id="lab_good_RealEstateAndAccumulatedDepreciationYearOfConstructionOrImprovements_label_en-US" xlink:label="lab_good_RealEstateAndAccumulatedDepreciationYearOfConstructionOrImprovements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate and Accumulated Depreciation, Year of Construction or Improvements </link:label>

<link:label id="lab_good_RealEstateAndAccumulatedDepreciationYearOfConstructionOrImprovements_documentation_en-US" xlink:label="lab_good_RealEstateAndAccumulatedDepreciationYearOfConstructionOrImprovements" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Year real estate investment property was constructed or improved for entities with a substantial portion of business acquiring and holding investment real estate, in CCYY format. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_RealEstateAndAccumulatedDepreciationYearOfConstructionOrImprovements" xlink:href="good-20221231.xsd#good_RealEstateAndAccumulatedDepreciationYearOfConstructionOrImprovements"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_RealEstateAndAccumulatedDepreciationYearOfConstructionOrImprovements" xlink:to="lab_good_RealEstateAndAccumulatedDepreciationYearOfConstructionOrImprovements" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LongTermDebt_8e038523-455a-4001-a0f1-24f35cda7b30_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebt" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term debt </link:label>

<link:label id="lab_us-gaap_LongTermDebt_12802cf0-86e8-4e2d-92bf-ebe4617dee65_totalLabel_en-US" xlink:label="lab_us-gaap_LongTermDebt" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term debt </link:label>

<link:label id="lab_us-gaap_LongTermDebt_label_en-US" xlink:label="lab_us-gaap_LongTermDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebt"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebt" xlink:to="lab_us-gaap_LongTermDebt" xlink:type="arc" order="1"/>

<link:label id="lab_good_SubsidiariesTwoMember_15b7fe4a-79ac-4cf3-8e1c-fdf6cc0bff56_terseLabel_en-US" xlink:label="lab_good_SubsidiariesTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gladstone Commercial Advisers, Inc. </link:label>

<link:label id="lab_good_SubsidiariesTwoMember_label_en-US" xlink:label="lab_good_SubsidiariesTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsidiaries Two [Member] </link:label>

<link:label id="lab_good_SubsidiariesTwoMember_documentation_en-US" xlink:label="lab_good_SubsidiariesTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsidiaries two. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SubsidiariesTwoMember" xlink:href="good-20221231.xsd#good_SubsidiariesTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SubsidiariesTwoMember" xlink:to="lab_good_SubsidiariesTwoMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SaleOfStockPricePerShare_0f8c06f8-b340-49e0-862a-b9df345ca0ff_terseLabel_en-US" xlink:label="lab_us-gaap_SaleOfStockPricePerShare" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale of stock, price per share (in dollars per share) </link:label>

<link:label id="lab_us-gaap_SaleOfStockPricePerShare_label_en-US" xlink:label="lab_us-gaap_SaleOfStockPricePerShare" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale of Stock, Price Per Share </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SaleOfStockPricePerShare"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SaleOfStockPricePerShare" xlink:to="lab_us-gaap_SaleOfStockPricePerShare" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_778eab2c-e79f-45b0-81eb-42f03feb5bcc_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Related Party Transactions, by Related Party [Table] </link:label>

<link:label id="lab_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Related Party Transactions, by Related Party [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="lab_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ReconciliationOfRealEstateAccumulatedDepreciationRollForward_388f651e-4447-4c99-ae6c-3adacbb6305c_terseLabel_en-US" xlink:label="lab_us-gaap_ReconciliationOfRealEstateAccumulatedDepreciationRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation [Roll Forward] </link:label>

<link:label id="lab_us-gaap_ReconciliationOfRealEstateAccumulatedDepreciationRollForward_label_en-US" xlink:label="lab_us-gaap_ReconciliationOfRealEstateAccumulatedDepreciationRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation [Roll Forward] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReconciliationOfRealEstateAccumulatedDepreciationRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ReconciliationOfRealEstateAccumulatedDepreciationRollForward"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ReconciliationOfRealEstateAccumulatedDepreciationRollForward" xlink:to="lab_us-gaap_ReconciliationOfRealEstateAccumulatedDepreciationRollForward" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_TemporaryEquityAbstract_4934f6bd-9cf3-4f91-a4b3-b42757cbc253_terseLabel_en-US" xlink:label="lab_us-gaap_TemporaryEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> MEZZANINE EQUITY </link:label>

<link:label id="lab_us-gaap_TemporaryEquityAbstract_label_en-US" xlink:label="lab_us-gaap_TemporaryEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Temporary Equity [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TemporaryEquityAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TemporaryEquityAbstract" xlink:to="lab_us-gaap_TemporaryEquityAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_9cc8542a-cc7f-4e3b-b0fe-d4558a8db0e3_terseLabel_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accumulated other comprehensive income </link:label>

<link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_label_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accumulated Other Comprehensive Income (Loss), Net of Tax </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:to="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy_378502cf-6750-428e-911d-9ad6d093aa29_terseLabel_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Restricted Cash </link:label>

<link:label id="lab_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy_label_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:to="lab_us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DebtInstrumentMaturityDate_4b519a23-a836-433d-8788-49ce5752d0cb_verboseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentMaturityDate" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Scheduled maturity dates </link:label>

<link:label id="lab_us-gaap_DebtInstrumentMaturityDate_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentMaturityDate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Maturity Date </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentMaturityDate" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentMaturityDate"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentMaturityDate" xlink:to="lab_us-gaap_DebtInstrumentMaturityDate" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntitySmallBusiness_029d2a8a-2483-4f49-8a33-0c6a83222c56_terseLabel_en-US" xlink:label="lab_dei_EntitySmallBusiness" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Small Business </link:label>

<link:label id="lab_dei_EntitySmallBusiness_label_en-US" xlink:label="lab_dei_EntitySmallBusiness" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Small Business </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntitySmallBusiness"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntitySmallBusiness" xlink:to="lab_dei_EntitySmallBusiness" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OtherCommitmentsTable_59dd232b-a094-4615-926b-0afa250dae24_terseLabel_en-US" xlink:label="lab_us-gaap_OtherCommitmentsTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Commitments [Table] </link:label>

<link:label id="lab_us-gaap_OtherCommitmentsTable_label_en-US" xlink:label="lab_us-gaap_OtherCommitmentsTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Commitments [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsTable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherCommitmentsTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherCommitmentsTable" xlink:to="lab_us-gaap_OtherCommitmentsTable" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense_ad32502a-55bb-4d92-900d-6640d76fae21_verboseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of right-of-use asset from operating leases and operating lease liabilities, net </link:label>

<link:label id="lab_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Lease, Right-of-Use Asset, Amortization Expense </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense" xlink:to="lab_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CommonStockDividendsPerShareDeclared_00a13676-6cb1-4502-bb3f-5733cb8c3a26_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockDividendsPerShareDeclared" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Distributions declared per common share (in dollars per share) </link:label>

<link:label id="lab_us-gaap_CommonStockDividendsPerShareDeclared_label_en-US" xlink:label="lab_us-gaap_CommonStockDividendsPerShareDeclared" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock, Dividends, Per Share, Declared </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockDividendsPerShareDeclared" xlink:to="lab_us-gaap_CommonStockDividendsPerShareDeclared" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RevenuesAbstract_84c9b24d-2d22-4a54-8c11-066ea4f7deba_terseLabel_en-US" xlink:label="lab_us-gaap_RevenuesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating revenues </link:label>

<link:label id="lab_us-gaap_RevenuesAbstract_label_en-US" xlink:label="lab_us-gaap_RevenuesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenues [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenuesAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenuesAbstract" xlink:to="lab_us-gaap_RevenuesAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsNet_aac7fc7b-2a3e-40ad-a6ac-1b724955f13e_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease intangibles, net </link:label>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsNet_2182ce60-e047-4927-afc8-624ef9d93f1a_totalLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease intangibles, net </link:label>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsNet_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets, Net </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RestrictedCash_33a85671-cdae-4c3b-9e44-f817a146a0f0_terseLabel_en-US" xlink:label="lab_us-gaap_RestrictedCash" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Restricted cash </link:label>

<link:label id="lab_us-gaap_RestrictedCash_label_en-US" xlink:label="lab_us-gaap_RestrictedCash" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Restricted Cash </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCash" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedCash"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RestrictedCash" xlink:to="lab_us-gaap_RestrictedCash" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_4b090780-583e-4866-9afd-d94d1034b712_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Distributions declared to common, senior common, preferred stockholders and Non-controlling OP Unit holders </link:label>

<link:label id="lab_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_label_en-US" xlink:label="lab_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:to="lab_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AmortizationOfDebtDiscountPremium_1b804259-dc84-4751-8f14-5fbf6209de4f_terseLabel_en-US" xlink:label="lab_us-gaap_AmortizationOfDebtDiscountPremium" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of discount and premium on assumed debt, net </link:label>

<link:label id="lab_us-gaap_AmortizationOfDebtDiscountPremium_label_en-US" xlink:label="lab_us-gaap_AmortizationOfDebtDiscountPremium" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of Debt Discount (Premium) </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfDebtDiscountPremium" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AmortizationOfDebtDiscountPremium"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AmortizationOfDebtDiscountPremium" xlink:to="lab_us-gaap_AmortizationOfDebtDiscountPremium" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain_5caae1be-69bd-43ea-9787-58a92835c18c_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment, Type [Domain] </link:label>

<link:label id="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Lived Tangible Asset [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateGrossAtCarryingValue_15d12b8b-1e9b-4197-89f2-082ebc0d07cd_totalLabel_en-US" xlink:label="lab_us-gaap_RealEstateGrossAtCarryingValue" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total </link:label>

<link:label id="lab_us-gaap_RealEstateGrossAtCarryingValue_f0b249f5-52d5-4356-bf21-0cbf06d9224a_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstateGrossAtCarryingValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total gross cost </link:label>

<link:label id="lab_us-gaap_RealEstateGrossAtCarryingValue_e25a2dad-7c40-4ecc-b659-ac64801787c0_periodStartLabel_en-US" xlink:label="lab_us-gaap_RealEstateGrossAtCarryingValue" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Balance at beginning of period </link:label>

<link:label id="lab_us-gaap_RealEstateGrossAtCarryingValue_eccd05da-b8bb-44cd-97b4-e94bc110ba6f_periodEndLabel_en-US" xlink:label="lab_us-gaap_RealEstateGrossAtCarryingValue" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Balance at end of period </link:label>

<link:label id="lab_us-gaap_RealEstateGrossAtCarryingValue_label_en-US" xlink:label="lab_us-gaap_RealEstateGrossAtCarryingValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateGrossAtCarryingValue" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateGrossAtCarryingValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateGrossAtCarryingValue" xlink:to="lab_us-gaap_RealEstateGrossAtCarryingValue" xlink:type="arc" order="1"/>

<link:label id="lab_srt_ConsolidatedEntitiesAxis_61117474-7e83-48fb-8761-fd0be97e0b6d_terseLabel_en-US" xlink:label="lab_srt_ConsolidatedEntitiesAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Consolidated Entities [Axis] </link:label>

<link:label id="lab_srt_ConsolidatedEntitiesAxis_label_en-US" xlink:label="lab_srt_ConsolidatedEntitiesAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Consolidated Entities [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidatedEntitiesAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ConsolidatedEntitiesAxis" xlink:to="lab_srt_ConsolidatedEntitiesAxis" xlink:type="arc" order="1"/>

<link:label id="lab_good_LakeMaryFloridaOfficeBuildingMember_bc6828cc-26e3-40eb-88cb-a49c45cd675a_terseLabel_en-US" xlink:label="lab_good_LakeMaryFloridaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lake Mary, Florida Office Building </link:label>

<link:label id="lab_good_LakeMaryFloridaOfficeBuildingMember_label_en-US" xlink:label="lab_good_LakeMaryFloridaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lake Mary, Florida Office Building [Member] </link:label>

<link:label id="lab_good_LakeMaryFloridaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_LakeMaryFloridaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lake Mary, Florida Office Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_LakeMaryFloridaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_LakeMaryFloridaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_LakeMaryFloridaOfficeBuildingMember" xlink:to="lab_good_LakeMaryFloridaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_CrandallGeorgiaIndustrialBuildingMember_96c8f024-dded-46c7-8537-860eb0aa96ba_terseLabel_en-US" xlink:label="lab_good_CrandallGeorgiaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Crandall, Georgia Industrial Building </link:label>

<link:label id="lab_good_CrandallGeorgiaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_CrandallGeorgiaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Crandall, Georgia Industrial Building [Member] </link:label>

<link:label id="lab_good_CrandallGeorgiaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_CrandallGeorgiaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Crandall, Georgia Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CrandallGeorgiaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_CrandallGeorgiaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CrandallGeorgiaIndustrialBuildingMember" xlink:to="lab_good_CrandallGeorgiaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableTable_5038a987-e6b7-410d-8f94-8af9cd28b865_terseLabel_en-US" xlink:label="lab_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Operating Leases Future Minimum Payments Receivable [Table] </link:label>

<link:label id="lab_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableTable_label_en-US" xlink:label="lab_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Operating Leases Future Minimum Payments Receivable [Table] </link:label>

<link:label id="lab_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableTable_documentation_en-US" xlink:label="lab_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableTable" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Operating Leases Future Minimum Payments Receivable [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableTable" xlink:href="good-20221231.xsd#good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableTable" xlink:to="lab_good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableTable" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DebtInstrumentLineItems_29011167-c0a2-49c0-a48f-eec50e22abe7_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument [Line Items] </link:label>

<link:label id="lab_us-gaap_DebtInstrumentLineItems_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentLineItems" xlink:to="lab_us-gaap_DebtInstrumentLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationDisclosureAbstract_521c977b-dce5-4e92-8000-189c9845eaf5_terseLabel_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract] </link:label>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationDisclosureAbstract_label_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationDisclosureAbstract" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RealEstateAndAccumulatedDepreciationDisclosureAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationDisclosureAbstract" xlink:to="lab_srt_RealEstateAndAccumulatedDepreciationDisclosureAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ClassOfStockLineItems_e0fd4bba-beda-4092-a78a-2ca53960d2b9_terseLabel_en-US" xlink:label="lab_us-gaap_ClassOfStockLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Class of Stock [Line Items] </link:label>

<link:label id="lab_us-gaap_ClassOfStockLineItems_label_en-US" xlink:label="lab_us-gaap_ClassOfStockLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Class of Stock [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ClassOfStockLineItems" xlink:to="lab_us-gaap_ClassOfStockLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberofNonCorePropertiesSold_9407c470-5524-47cb-85a2-3c575c638729_verboseLabel_en-US" xlink:label="lab_good_NumberofNonCorePropertiesSold" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of non-core properties sold </link:label>

<link:label id="lab_good_NumberofNonCorePropertiesSold_label_en-US" xlink:label="lab_good_NumberofNonCorePropertiesSold" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Non-Core Properties Sold </link:label>

<link:label id="lab_good_NumberofNonCorePropertiesSold_documentation_en-US" xlink:label="lab_good_NumberofNonCorePropertiesSold" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Non-Core Properties Sold </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberofNonCorePropertiesSold" xlink:href="good-20221231.xsd#good_NumberofNonCorePropertiesSold"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberofNonCorePropertiesSold" xlink:to="lab_good_NumberofNonCorePropertiesSold" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OperatingLeaseLiability_717c5046-02dd-4f8a-8373-16aba91ab634_verboseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating lease liabilities </link:label>

<link:label id="lab_us-gaap_OperatingLeaseLiability_ae6bad93-6e39-48a7-813e-8bc1c9bb22f7_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Present value of lease payments </link:label>

<link:label id="lab_us-gaap_OperatingLeaseLiability_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Lease, Liability </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseLiability"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLiability" xlink:to="lab_us-gaap_OperatingLeaseLiability" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_Land_dd8d9c76-dc18-4022-8e98-62a41a43466e_terseLabel_en-US" xlink:label="lab_us-gaap_Land" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Land </link:label>

<link:label id="lab_us-gaap_Land_label_en-US" xlink:label="lab_us-gaap_Land" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Land </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Land" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Land"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Land" xlink:to="lab_us-gaap_Land" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_d6d4cd59-f68a-4652-a4b1-6b47acded595_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2024 </link:label>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Asset, Expected Amortization, Year Two </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:type="arc" order="1"/>

<link:label id="lab_good_PaymentPeriodForTerminationOfAgreement_9dc92841-ad6a-4d32-9201-a44d5193a8c6_terseLabel_en-US" xlink:label="lab_good_PaymentPeriodForTerminationOfAgreement" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payment period for termination of agreement </link:label>

<link:label id="lab_good_PaymentPeriodForTerminationOfAgreement_label_en-US" xlink:label="lab_good_PaymentPeriodForTerminationOfAgreement" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payment Period For Termination Of Agreement </link:label>

<link:label id="lab_good_PaymentPeriodForTerminationOfAgreement_documentation_en-US" xlink:label="lab_good_PaymentPeriodForTerminationOfAgreement" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payment Period For Termination Of Agreement </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PaymentPeriodForTerminationOfAgreement" xlink:href="good-20221231.xsd#good_PaymentPeriodForTerminationOfAgreement"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PaymentPeriodForTerminationOfAgreement" xlink:to="lab_good_PaymentPeriodForTerminationOfAgreement" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceived_3b84913a-a84e-4e28-9630-b9863aa007b9_totalLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceived" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tenant lease payments </link:label>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceived_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceived" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessor, Operating Lease, Payments to be Received </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceived" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceived"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceived" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceived" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_e9ae86d1-7658-4d85-833c-8458b1680f50_terseLabel_en-US" xlink:label="lab_us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net proceeds from sale of shares </link:label>

<link:label id="lab_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_label_en-US" xlink:label="lab_us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale of Stock, Consideration Received on Transaction </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:to="lab_us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:type="arc" order="1"/>

<link:label id="lab_good_NoncashOrPartNoncashPaymentsToAcquireRealEstateAndIntangibleAsset_d7ec23a9-0ae7-40c9-9efc-498d08806f87_terseLabel_en-US" xlink:label="lab_good_NoncashOrPartNoncashPaymentsToAcquireRealEstateAndIntangibleAsset" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Acquisition of real estate and related intangible assets </link:label>

<link:label id="lab_good_NoncashOrPartNoncashPaymentsToAcquireRealEstateAndIntangibleAsset_label_en-US" xlink:label="lab_good_NoncashOrPartNoncashPaymentsToAcquireRealEstateAndIntangibleAsset" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncash or Part Noncash, Payments To Acquire Real Estate And Intangible Asset </link:label>

<link:label id="lab_good_NoncashOrPartNoncashPaymentsToAcquireRealEstateAndIntangibleAsset_documentation_en-US" xlink:label="lab_good_NoncashOrPartNoncashPaymentsToAcquireRealEstateAndIntangibleAsset" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncash or Part Noncash, Payments To Acquire Real Estate And Intangible Asset </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NoncashOrPartNoncashPaymentsToAcquireRealEstateAndIntangibleAsset" xlink:href="good-20221231.xsd#good_NoncashOrPartNoncashPaymentsToAcquireRealEstateAndIntangibleAsset"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NoncashOrPartNoncashPaymentsToAcquireRealEstateAndIntangibleAsset" xlink:to="lab_good_NoncashOrPartNoncashPaymentsToAcquireRealEstateAndIntangibleAsset" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_IncreaseDecreaseInOtherOperatingAssets_fc421511-f03b-4e00-93e9-e8d7a1bd7833_negatedLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> (Increase) decrease in other assets </link:label>

<link:label id="lab_us-gaap_IncreaseDecreaseInOtherOperatingAssets_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Other Operating Assets </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:to="lab_us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberOfPropertiesIssuedToCollateralizedMortgageNotesPayable_9752bd92-068c-471e-bf6a-f365c2b3f764_terseLabel_en-US" xlink:label="lab_good_NumberOfPropertiesIssuedToCollateralizedMortgageNotesPayable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of properties to issue collateralized mortgage notes payable </link:label>

<link:label id="lab_good_NumberOfPropertiesIssuedToCollateralizedMortgageNotesPayable_label_en-US" xlink:label="lab_good_NumberOfPropertiesIssuedToCollateralizedMortgageNotesPayable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Properties Issued To Collateralized Mortgage Notes Payable </link:label>

<link:label id="lab_good_NumberOfPropertiesIssuedToCollateralizedMortgageNotesPayable_documentation_en-US" xlink:label="lab_good_NumberOfPropertiesIssuedToCollateralizedMortgageNotesPayable" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Properties Issued To Collateralized Mortgage Notes Payable </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberOfPropertiesIssuedToCollateralizedMortgageNotesPayable" xlink:href="good-20221231.xsd#good_NumberOfPropertiesIssuedToCollateralizedMortgageNotesPayable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberOfPropertiesIssuedToCollateralizedMortgageNotesPayable" xlink:to="lab_good_NumberOfPropertiesIssuedToCollateralizedMortgageNotesPayable" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_49483306-ac9f-41cc-878d-b205a0f3c68f_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2026 </link:label>

<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Maturity, Year Four </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_HedgingDesignationAxis_f9a73ebc-daa5-48fe-b4ce-992045bdf26a_terseLabel_en-US" xlink:label="lab_us-gaap_HedgingDesignationAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hedging Designation [Axis] </link:label>

<link:label id="lab_us-gaap_HedgingDesignationAxis_label_en-US" xlink:label="lab_us-gaap_HedgingDesignationAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hedging Designation [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_HedgingDesignationAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_HedgingDesignationAxis" xlink:to="lab_us-gaap_HedgingDesignationAxis" xlink:type="arc" order="1"/>

<link:label id="lab_dei_AuditorLocation_8019fac2-357f-4141-88dd-a149f4d81942_terseLabel_en-US" xlink:label="lab_dei_AuditorLocation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Auditor Location </link:label>

<link:label id="lab_dei_AuditorLocation_label_en-US" xlink:label="lab_dei_AuditorLocation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Auditor Location </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_AuditorLocation" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_AuditorLocation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_AuditorLocation" xlink:to="lab_dei_AuditorLocation" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityFilerCategory_39ea9973-dafa-41e5-8ac5-41926ec694ed_terseLabel_en-US" xlink:label="lab_dei_EntityFilerCategory" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Filer Category </link:label>

<link:label id="lab_dei_EntityFilerCategory_label_en-US" xlink:label="lab_dei_EntityFilerCategory" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Filer Category </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityFilerCategory"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityFilerCategory" xlink:to="lab_dei_EntityFilerCategory" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberOfSubsidiariesInterestOwnedInGeneralAndLimitedPartnership_799bbd0f-7d2c-4410-8a24-76f09ffa7624_terseLabel_en-US" xlink:label="lab_good_NumberOfSubsidiariesInterestOwnedInGeneralAndLimitedPartnership" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of subsidiaries interest owned in general and limited partnership </link:label>

<link:label id="lab_good_NumberOfSubsidiariesInterestOwnedInGeneralAndLimitedPartnership_label_en-US" xlink:label="lab_good_NumberOfSubsidiariesInterestOwnedInGeneralAndLimitedPartnership" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Subsidiaries Interest Owned In General And Limited Partnership </link:label>

<link:label id="lab_good_NumberOfSubsidiariesInterestOwnedInGeneralAndLimitedPartnership_documentation_en-US" xlink:label="lab_good_NumberOfSubsidiariesInterestOwnedInGeneralAndLimitedPartnership" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of subsidiaries interest owned in general and limited partnership. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberOfSubsidiariesInterestOwnedInGeneralAndLimitedPartnership" xlink:href="good-20221231.xsd#good_NumberOfSubsidiariesInterestOwnedInGeneralAndLimitedPartnership"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberOfSubsidiariesInterestOwnedInGeneralAndLimitedPartnership" xlink:to="lab_good_NumberOfSubsidiariesInterestOwnedInGeneralAndLimitedPartnership" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_BusinessCombinationAcquiredDirectFinancingLeaseReceivable_0296b9ab-b359-4552-9f60-2c2a148871dd_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationAcquiredDirectFinancingLeaseReceivable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loans receivable </link:label>

<link:label id="lab_us-gaap_BusinessCombinationAcquiredDirectFinancingLeaseReceivable_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationAcquiredDirectFinancingLeaseReceivable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Acquired Direct Financing Lease Receivable </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquiredDirectFinancingLeaseReceivable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationAcquiredDirectFinancingLeaseReceivable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationAcquiredDirectFinancingLeaseReceivable" xlink:to="lab_us-gaap_BusinessCombinationAcquiredDirectFinancingLeaseReceivable" xlink:type="arc" order="1"/>

<link:label id="lab_good_WilmingtonNorthCarolinaIndustrialBuildingMember_db2abab0-2858-441a-bbd6-cd9fe6b6541b_terseLabel_en-US" xlink:label="lab_good_WilmingtonNorthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilmington, North Carolina Industrial Building </link:label>

<link:label id="lab_good_WilmingtonNorthCarolinaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_WilmingtonNorthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilmington, North Carolina Industrial Building [Member] </link:label>

<link:label id="lab_good_WilmingtonNorthCarolinaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_WilmingtonNorthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilmington, North Carolina Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_WilmingtonNorthCarolinaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_WilmingtonNorthCarolinaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_WilmingtonNorthCarolinaIndustrialBuildingMember" xlink:to="lab_good_WilmingtonNorthCarolinaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_srt_MortgageLoansOnRealEstateFaceAmountOfMortgages_3591d318-c0ad-47a2-a160-8d0bfa883427_verboseLabel_en-US" xlink:label="lab_srt_MortgageLoansOnRealEstateFaceAmountOfMortgages" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net book value of collateralized mortgage properties </link:label>

<link:label id="lab_srt_MortgageLoansOnRealEstateFaceAmountOfMortgages_bc61160b-d072-4347-9705-a668c8ea4359_terseLabel_en-US" xlink:label="lab_srt_MortgageLoansOnRealEstateFaceAmountOfMortgages" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Face Amount of Mortgage </link:label>

<link:label id="lab_srt_MortgageLoansOnRealEstateFaceAmountOfMortgages_label_en-US" xlink:label="lab_srt_MortgageLoansOnRealEstateFaceAmountOfMortgages" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_MortgageLoansOnRealEstateFaceAmountOfMortgages" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MortgageLoansOnRealEstateFaceAmountOfMortgages"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_MortgageLoansOnRealEstateFaceAmountOfMortgages" xlink:to="lab_srt_MortgageLoansOnRealEstateFaceAmountOfMortgages" xlink:type="arc" order="1"/>

<link:label id="lab_good_AnnualBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses_3d554d23-f4ea-470d-b9e0-a33cdb5dacf2_terseLabel_en-US" xlink:label="lab_good_AnnualBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Annual base management fee, in percentage of stockholders' equity, adjusted to unrealized gains or losses </link:label>

<link:label id="lab_good_AnnualBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses_label_en-US" xlink:label="lab_good_AnnualBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Annual Base Management Fee In Percentage Of Stockholders Equity Adjusted To Unrealized Gains Or Losses </link:label>

<link:label id="lab_good_AnnualBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses_documentation_en-US" xlink:label="lab_good_AnnualBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Annual base management fee in percentage of stockholders equity adjusted to unrealized gains or losses. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AnnualBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses" xlink:href="good-20221231.xsd#good_AnnualBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AnnualBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses" xlink:to="lab_good_AnnualBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NoncashInvestingAndFinancingItemsAbstract_9dd37db3-def2-4588-a906-7352c61edc91_terseLabel_en-US" xlink:label="lab_us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SUPPLEMENTAL AND NON-CASH INFORMATION </link:label>

<link:label id="lab_us-gaap_NoncashInvestingAndFinancingItemsAbstract_label_en-US" xlink:label="lab_us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncash Investing and Financing Items [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NoncashInvestingAndFinancingItemsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="lab_us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_CommitmentsAndContingencies_b37bb530-ad75-4009-aaea-66be9c5ad66a_terseLabel_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingencies" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commitments and contingencies </link:label>

<link:label id="lab_us-gaap_CommitmentsAndContingencies_label_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingencies" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commitments and Contingencies </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommitmentsAndContingencies"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommitmentsAndContingencies" xlink:to="lab_us-gaap_CommitmentsAndContingencies" xlink:type="arc" order="1"/>

<link:label id="lab_dei_SecurityExchangeName_0c245dd0-b544-45b9-802c-72c4590b3f9f_terseLabel_en-US" xlink:label="lab_dei_SecurityExchangeName" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Security Exchange Name </link:label>

<link:label id="lab_dei_SecurityExchangeName_label_en-US" xlink:label="lab_dei_SecurityExchangeName" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Security Exchange Name </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_SecurityExchangeName"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_SecurityExchangeName" xlink:to="lab_dei_SecurityExchangeName" xlink:type="arc" order="1"/>

<link:label id="lab_good_WilmingtonNorthCarolinaMember_13fb0548-3af1-4a25-a0a7-630239ddafc2_terseLabel_en-US" xlink:label="lab_good_WilmingtonNorthCarolinaMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilmington, North Carolina </link:label>

<link:label id="lab_good_WilmingtonNorthCarolinaMember_label_en-US" xlink:label="lab_good_WilmingtonNorthCarolinaMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilmington, North Carolina [Member] </link:label>

<link:label id="lab_good_WilmingtonNorthCarolinaMember_documentation_en-US" xlink:label="lab_good_WilmingtonNorthCarolinaMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Wilmington, North Carolina </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_WilmingtonNorthCarolinaMember" xlink:href="good-20221231.xsd#good_WilmingtonNorthCarolinaMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_WilmingtonNorthCarolinaMember" xlink:to="lab_good_WilmingtonNorthCarolinaMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_PercentageOfDiscountRateForCalculatingUndiscountedObligation_4434dcad-d0de-4a47-a275-e2a226fd35b2_terseLabel_en-US" xlink:label="lab_good_PercentageOfDiscountRateForCalculatingUndiscountedObligation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of discount rate for calculating undiscounted obligation </link:label>

<link:label id="lab_good_PercentageOfDiscountRateForCalculatingUndiscountedObligation_label_en-US" xlink:label="lab_good_PercentageOfDiscountRateForCalculatingUndiscountedObligation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage Of Discount Rate For Calculating Undiscounted Obligation </link:label>

<link:label id="lab_good_PercentageOfDiscountRateForCalculatingUndiscountedObligation_documentation_en-US" xlink:label="lab_good_PercentageOfDiscountRateForCalculatingUndiscountedObligation" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of discount rate for calculating undiscounted obligation. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PercentageOfDiscountRateForCalculatingUndiscountedObligation" xlink:href="good-20221231.xsd#good_PercentageOfDiscountRateForCalculatingUndiscountedObligation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PercentageOfDiscountRateForCalculatingUndiscountedObligation" xlink:to="lab_good_PercentageOfDiscountRateForCalculatingUndiscountedObligation" xlink:type="arc" order="1"/>

<link:label id="lab_good_DetroitMichiganIndustrialBuildingMember_16210024-6c69-4dd7-b1ee-2fcfc32ab4e1_terseLabel_en-US" xlink:label="lab_good_DetroitMichiganIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Detroit, Michigan Industrial Building </link:label>

<link:label id="lab_good_DetroitMichiganIndustrialBuildingMember_label_en-US" xlink:label="lab_good_DetroitMichiganIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Detroit, Michigan Industrial Building [Member] </link:label>

<link:label id="lab_good_DetroitMichiganIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_DetroitMichiganIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Detroit, Michigan Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DetroitMichiganIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_DetroitMichiganIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DetroitMichiganIndustrialBuildingMember" xlink:to="lab_good_DetroitMichiganIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_99af0193-fbf0-4788-9ab4-0c2652a3c96c_terseLabel_en-US" xlink:label="lab_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted average amortization period </link:label>

<link:label id="lab_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_label_en-US" xlink:label="lab_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:to="lab_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StockIssued1_e8c14dd5-3a3d-4749-b569-9777d256b309_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssued1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Non-controlling OP Units issued in connection with acquisition </link:label>

<link:label id="lab_us-gaap_StockIssued1_label_en-US" xlink:label="lab_us-gaap_StockIssued1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Issued </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssued1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssued1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssued1" xlink:to="lab_us-gaap_StockIssued1" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax_fe11fd47-0c91-4468-9213-24150363dc05_negatedLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reclassification into interest expense </link:label>

<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax_144afc7d-e9d1-4520-a205-68891b909a3c_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amount reclassified out of Accumulated Other Comprehensive Income </link:label>

<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax" xlink:to="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LettersOfCreditOutstandingAmount_046d3fc9-d8f5-4799-a16c-a32a61bd68ed_terseLabel_en-US" xlink:label="lab_us-gaap_LettersOfCreditOutstandingAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Letters of credit, outstanding </link:label>

<link:label id="lab_us-gaap_LettersOfCreditOutstandingAmount_label_en-US" xlink:label="lab_us-gaap_LettersOfCreditOutstandingAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Letters of Credit Outstanding, Amount </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LettersOfCreditOutstandingAmount" xlink:to="lab_us-gaap_LettersOfCreditOutstandingAmount" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_5ea497f3-9ae6-4f41-8e31-e2e452865d3c_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Conversion of senior common stock to common stock (in shares) </link:label>

<link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_label_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Issued During Period, Shares, Conversion of Convertible Securities </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:to="lab_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:type="arc" order="1"/>

<link:label id="lab_good_MonroeMichiganIndustrialBuildingTwoMember_af6eed9f-882f-4fb9-877c-6423f3e63a86_terseLabel_en-US" xlink:label="lab_good_MonroeMichiganIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Monroe, Michigan Industrial Building </link:label>

<link:label id="lab_good_MonroeMichiganIndustrialBuildingTwoMember_label_en-US" xlink:label="lab_good_MonroeMichiganIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Monroe, Michigan Industrial Building Two [Member] </link:label>

<link:label id="lab_good_MonroeMichiganIndustrialBuildingTwoMember_documentation_en-US" xlink:label="lab_good_MonroeMichiganIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Monroe, Michigan Industrial Building Two [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_MonroeMichiganIndustrialBuildingTwoMember" xlink:href="good-20221231.xsd#good_MonroeMichiganIndustrialBuildingTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_MonroeMichiganIndustrialBuildingTwoMember" xlink:to="lab_good_MonroeMichiganIndustrialBuildingTwoMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DividendsDomain_5dfe48e2-7e49-4bf6-ab8d-d96c302da56b_terseLabel_en-US" xlink:label="lab_us-gaap_DividendsDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividends [Domain] </link:label>

<link:label id="lab_us-gaap_DividendsDomain_label_en-US" xlink:label="lab_us-gaap_DividendsDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividends [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DividendsDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DividendsDomain" xlink:to="lab_us-gaap_DividendsDomain" xlink:type="arc" order="1"/>

<link:label id="lab_dei_CoverAbstract_label_en-US" xlink:label="lab_dei_CoverAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cover [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_CoverAbstract" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_CoverAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_CoverAbstract" xlink:to="lab_dei_CoverAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_VinelandNewJerseyIndustrialBuildingMember_890559cd-9508-4348-89b1-3104d12ee2c4_terseLabel_en-US" xlink:label="lab_good_VinelandNewJerseyIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vineland, New Jersey, Industrial Building </link:label>

<link:label id="lab_good_VinelandNewJerseyIndustrialBuildingMember_label_en-US" xlink:label="lab_good_VinelandNewJerseyIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vineland, New Jersey, Industrial Building [Member] </link:label>

<link:label id="lab_good_VinelandNewJerseyIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_VinelandNewJerseyIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vineland, New Jersey, Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_VinelandNewJerseyIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_VinelandNewJerseyIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_VinelandNewJerseyIndustrialBuildingMember" xlink:to="lab_good_VinelandNewJerseyIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityVoluntaryFilers_2270858a-ffa2-46c7-ac1c-9cd26f34c41b_terseLabel_en-US" xlink:label="lab_dei_EntityVoluntaryFilers" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Voluntary Filers </link:label>

<link:label id="lab_dei_EntityVoluntaryFilers_label_en-US" xlink:label="lab_dei_EntityVoluntaryFilers" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Voluntary Filers </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityVoluntaryFilers" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityVoluntaryFilers"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityVoluntaryFilers" xlink:to="lab_dei_EntityVoluntaryFilers" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DepreciationAndAmortization_78de6b1c-1252-4f9a-a0d8-f303748d03e3_terseLabel_en-US" xlink:label="lab_us-gaap_DepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Depreciation and amortization </link:label>

<link:label id="lab_us-gaap_DepreciationAndAmortization_label_en-US" xlink:label="lab_us-gaap_DepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Depreciation, Depletion and Amortization, Nonproduction </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DepreciationAndAmortization"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DepreciationAndAmortization" xlink:to="lab_us-gaap_DepreciationAndAmortization" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation_79120c8d-e1a7-4188-be52-5ad3cb11ac08_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Less: accumulated depreciation </link:label>

<link:label id="lab_us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation_c1fc7086-f2bd-4703-a78e-5dc155b64a69_negatedLabel_en-US" xlink:label="lab_us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accumulated depreciation </link:label>

<link:label id="lab_us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation_label_en-US" xlink:label="lab_us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate Investment Property, Accumulated Depreciation </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation" xlink:to="lab_us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_c3d666f5-1db3-4499-989b-c02ea3e038cf_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] </link:label>

<link:label id="lab_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_label_en-US" xlink:label="lab_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:to="lab_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OtherAssets_2a12e38f-7b7f-47a0-a2e3-00980d9815f2_terseLabel_en-US" xlink:label="lab_us-gaap_OtherAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other assets </link:label>

<link:label id="lab_us-gaap_OtherAssets_label_en-US" xlink:label="lab_us-gaap_OtherAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Assets </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherAssets"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherAssets" xlink:to="lab_us-gaap_OtherAssets" xlink:type="arc" order="1"/>

<link:label id="lab_good_IncreaseDecreaseInAccountsPayableAndAccruedLiabilitiesDueToAdviserAndAdministrator_a0f11f6f-af37-47be-b086-e22c63b51ae3_terseLabel_en-US" xlink:label="lab_good_IncreaseDecreaseInAccountsPayableAndAccruedLiabilitiesDueToAdviserAndAdministrator" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> (Decrease) increase in amount due to Adviser and Administrator </link:label>

<link:label id="lab_good_IncreaseDecreaseInAccountsPayableAndAccruedLiabilitiesDueToAdviserAndAdministrator_label_en-US" xlink:label="lab_good_IncreaseDecreaseInAccountsPayableAndAccruedLiabilitiesDueToAdviserAndAdministrator" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Accounts Payable and Accrued Liabilities, Due to Adviser and Administrator </link:label>

<link:label id="lab_good_IncreaseDecreaseInAccountsPayableAndAccruedLiabilitiesDueToAdviserAndAdministrator_documentation_en-US" xlink:label="lab_good_IncreaseDecreaseInAccountsPayableAndAccruedLiabilitiesDueToAdviserAndAdministrator" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Accounts Payable and Accrued Liabilities, Due to Adviser and Administrator </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_IncreaseDecreaseInAccountsPayableAndAccruedLiabilitiesDueToAdviserAndAdministrator" xlink:href="good-20221231.xsd#good_IncreaseDecreaseInAccountsPayableAndAccruedLiabilitiesDueToAdviserAndAdministrator"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_IncreaseDecreaseInAccountsPayableAndAccruedLiabilitiesDueToAdviserAndAdministrator" xlink:to="lab_good_IncreaseDecreaseInAccountsPayableAndAccruedLiabilitiesDueToAdviserAndAdministrator" xlink:type="arc" order="1"/>

<link:label id="lab_good_IncreaseDecreaseInSecurityDeposit_f27ee5ad-9927-428d-b870-e94876f89f01_terseLabel_en-US" xlink:label="lab_good_IncreaseDecreaseInSecurityDeposit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (decrease) in security deposits </link:label>

<link:label id="lab_good_IncreaseDecreaseInSecurityDeposit_label_en-US" xlink:label="lab_good_IncreaseDecreaseInSecurityDeposit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Security Deposit </link:label>

<link:label id="lab_good_IncreaseDecreaseInSecurityDeposit_documentation_en-US" xlink:label="lab_good_IncreaseDecreaseInSecurityDeposit" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Security Deposit </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_IncreaseDecreaseInSecurityDeposit" xlink:href="good-20221231.xsd#good_IncreaseDecreaseInSecurityDeposit"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_IncreaseDecreaseInSecurityDeposit" xlink:to="lab_good_IncreaseDecreaseInSecurityDeposit" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ReconciliationOfCarryingAmountOfRealEstateInvestmentsRollForward_ed8cb5af-9c9a-416a-931c-f0e244d80cdc_terseLabel_en-US" xlink:label="lab_us-gaap_ReconciliationOfCarryingAmountOfRealEstateInvestmentsRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate [Roll Forward] </link:label>

<link:label id="lab_us-gaap_ReconciliationOfCarryingAmountOfRealEstateInvestmentsRollForward_label_en-US" xlink:label="lab_us-gaap_ReconciliationOfCarryingAmountOfRealEstateInvestmentsRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate [Roll Forward] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReconciliationOfCarryingAmountOfRealEstateInvestmentsRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ReconciliationOfCarryingAmountOfRealEstateInvestmentsRollForward"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ReconciliationOfCarryingAmountOfRealEstateInvestmentsRollForward" xlink:to="lab_us-gaap_ReconciliationOfCarryingAmountOfRealEstateInvestmentsRollForward" xlink:type="arc" order="1"/>

<link:label id="lab_dei_DocumentsIncorporatedByReferenceTextBlock_311612aa-8794-4789-8d4b-1718e92056a0_terseLabel_en-US" xlink:label="lab_dei_DocumentsIncorporatedByReferenceTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Documents Incorporated by Reference </link:label>

<link:label id="lab_dei_DocumentsIncorporatedByReferenceTextBlock_label_en-US" xlink:label="lab_dei_DocumentsIncorporatedByReferenceTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Documents Incorporated by Reference [Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentsIncorporatedByReferenceTextBlock" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentsIncorporatedByReferenceTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentsIncorporatedByReferenceTextBlock" xlink:to="lab_dei_DocumentsIncorporatedByReferenceTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquity_1f41293b-e970-4c90-8601-d32a1d633c7b_totalLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquity" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> TOTAL LIABILITIES, MEZZANINE EQUITY AND EQUITY </link:label>

<link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquity_label_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liabilities and Equity </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="lab_us-gaap_LiabilitiesAndStockholdersEquity" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ProceedsFromSaleOfPropertyHeldForSale_05d529e4-734c-4631-89f4-eea6c0fad05b_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromSaleOfPropertyHeldForSale" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate Sales Price </link:label>

<link:label id="lab_us-gaap_ProceedsFromSaleOfPropertyHeldForSale_label_en-US" xlink:label="lab_us-gaap_ProceedsFromSaleOfPropertyHeldForSale" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from Sale of Property Held-for-sale </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfPropertyHeldForSale" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromSaleOfPropertyHeldForSale"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromSaleOfPropertyHeldForSale" xlink:to="lab_us-gaap_ProceedsFromSaleOfPropertyHeldForSale" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AmortizationOfFinancingCosts_ad34f0c0-bd70-4097-a0c3-89b894589efd_terseLabel_en-US" xlink:label="lab_us-gaap_AmortizationOfFinancingCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of deferred financing costs </link:label>

<link:label id="lab_us-gaap_AmortizationOfFinancingCosts_ccfae059-38de-4c6b-9a08-c62a6acbf512_verboseLabel_en-US" xlink:label="lab_us-gaap_AmortizationOfFinancingCosts" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total amortization expense related to deferred financing costs is included in interest expense </link:label>

<link:label id="lab_us-gaap_AmortizationOfFinancingCosts_label_en-US" xlink:label="lab_us-gaap_AmortizationOfFinancingCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of Debt Issuance Costs </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AmortizationOfFinancingCosts"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AmortizationOfFinancingCosts" xlink:to="lab_us-gaap_AmortizationOfFinancingCosts" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LongtermDebtTypeAxis_25383b9f-7f7b-4c9b-93e3-777e6f761aa9_terseLabel_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term Debt, Type [Axis] </link:label>

<link:label id="lab_us-gaap_LongtermDebtTypeAxis_label_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Type [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongtermDebtTypeAxis" xlink:to="lab_us-gaap_LongtermDebtTypeAxis" xlink:type="arc" order="1"/>

<link:label id="lab_good_WeightedAverageSharesOfSeniorCommonStockOutstandingBasic_132ef4f7-06e8-463d-87de-6482f450b5e0_terseLabel_en-US" xlink:label="lab_good_WeightedAverageSharesOfSeniorCommonStockOutstandingBasic" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted average shares of senior common stock outstanding - basic (in shares) </link:label>

<link:label id="lab_good_WeightedAverageSharesOfSeniorCommonStockOutstandingBasic_label_en-US" xlink:label="lab_good_WeightedAverageSharesOfSeniorCommonStockOutstandingBasic" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Shares Of Senior Common Stock Outstanding Basic </link:label>

<link:label id="lab_good_WeightedAverageSharesOfSeniorCommonStockOutstandingBasic_documentation_en-US" xlink:label="lab_good_WeightedAverageSharesOfSeniorCommonStockOutstandingBasic" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted average shares of senior common stock outstanding - basic. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_WeightedAverageSharesOfSeniorCommonStockOutstandingBasic" xlink:href="good-20221231.xsd#good_WeightedAverageSharesOfSeniorCommonStockOutstandingBasic"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_WeightedAverageSharesOfSeniorCommonStockOutstandingBasic" xlink:to="lab_good_WeightedAverageSharesOfSeniorCommonStockOutstandingBasic" xlink:type="arc" order="1"/>

<link:label id="lab_good_ConshohockenPennsylvaniaOfficeBuildingMember_7cf5d4d5-70cd-4ca4-b9c2-c99c5475adcd_terseLabel_en-US" xlink:label="lab_good_ConshohockenPennsylvaniaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Conshohocken Pennsylvania Office Building </link:label>

<link:label id="lab_good_ConshohockenPennsylvaniaOfficeBuildingMember_label_en-US" xlink:label="lab_good_ConshohockenPennsylvaniaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Conshohocken Pennsylvania Office Building [Member] </link:label>

<link:label id="lab_good_ConshohockenPennsylvaniaOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_ConshohockenPennsylvaniaOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Conshohocken Pennsylvania Office Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ConshohockenPennsylvaniaOfficeBuildingMember" xlink:href="good-20221231.xsd#good_ConshohockenPennsylvaniaOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ConshohockenPennsylvaniaOfficeBuildingMember" xlink:to="lab_good_ConshohockenPennsylvaniaOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_AllenTexasRetailBuildingMember_c58b6c7c-f158-4df1-bb17-b7ab15fa3fd1_terseLabel_en-US" xlink:label="lab_good_AllenTexasRetailBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Allen, Texas Retail Building </link:label>

<link:label id="lab_good_AllenTexasRetailBuildingMember_label_en-US" xlink:label="lab_good_AllenTexasRetailBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Allen Texas Retail Building [Member] </link:label>

<link:label id="lab_good_AllenTexasRetailBuildingMember_documentation_en-US" xlink:label="lab_good_AllenTexasRetailBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Allen Texas Retail Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AllenTexasRetailBuildingMember" xlink:href="good-20221231.xsd#good_AllenTexasRetailBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AllenTexasRetailBuildingMember" xlink:to="lab_good_AllenTexasRetailBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_a7f616ce-e717-41c5-b5ce-d9e78708e2b3_negatedLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Less: amount representing interest </link:label>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, Undiscounted Excess Amount </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:type="arc" order="1"/>

<link:label id="lab_good_AccountsReceivableFromTenants_c4124e0e-47ff-4bd5-aa47-513ccbd15234_terseLabel_en-US" xlink:label="lab_good_AccountsReceivableFromTenants" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts receivable from tenants </link:label>

<link:label id="lab_good_AccountsReceivableFromTenants_label_en-US" xlink:label="lab_good_AccountsReceivableFromTenants" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts Receivable From Tenants </link:label>

<link:label id="lab_good_AccountsReceivableFromTenants_documentation_en-US" xlink:label="lab_good_AccountsReceivableFromTenants" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts Receivable From Tenants </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AccountsReceivableFromTenants" xlink:href="good-20221231.xsd#good_AccountsReceivableFromTenants"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AccountsReceivableFromTenants" xlink:to="lab_good_AccountsReceivableFromTenants" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_8ae58ff4-a95e-4455-bcca-937b8caf4a95_totalLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net (loss) income (attributable) available to common stockholders plus assumed conversions </link:label>

<link:label id="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_label_en-US" xlink:label="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Income (Loss) Available to Common Stockholders, Diluted </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:to="lab_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_EarningsPerShareDiluted_94958bf7-176a-408e-ab03-54b6c9c8bc11_verboseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareDiluted" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> (Loss) Income (attributable) available to common shareholders, Diluted (in dollars per share) </link:label>

<link:label id="lab_us-gaap_EarningsPerShareDiluted_4ad47bfd-3adf-4818-9a19-74da693a8b2f_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareDiluted" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Diluted (loss) earnings per share of common stock (in dollars per share) </link:label>

<link:label id="lab_us-gaap_EarningsPerShareDiluted_label_en-US" xlink:label="lab_us-gaap_EarningsPerShareDiluted" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings Per Share, Diluted </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerShareDiluted"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerShareDiluted" xlink:to="lab_us-gaap_EarningsPerShareDiluted" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_SaleOfStockNameOfTransactionDomain_8144414c-ff8b-4454-b0a5-d2f0484e1b20_terseLabel_en-US" xlink:label="lab_us-gaap_SaleOfStockNameOfTransactionDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale of Stock [Domain] </link:label>

<link:label id="lab_us-gaap_SaleOfStockNameOfTransactionDomain_label_en-US" xlink:label="lab_us-gaap_SaleOfStockNameOfTransactionDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale of Stock [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain" xlink:to="lab_us-gaap_SaleOfStockNameOfTransactionDomain" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PaymentsOfStockIssuanceCosts_3a46a399-6a8a-4b1d-967d-690003eef1a1_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsOfStockIssuanceCosts" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Offering costs paid </link:label>

<link:label id="lab_us-gaap_PaymentsOfStockIssuanceCosts_label_en-US" xlink:label="lab_us-gaap_PaymentsOfStockIssuanceCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments of Stock Issuance Costs </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfStockIssuanceCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsOfStockIssuanceCosts"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsOfStockIssuanceCosts" xlink:to="lab_us-gaap_PaymentsOfStockIssuanceCosts" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_MinorityInterestOwnershipPercentageByParent_134adac9-aae2-4a87-ab71-19274f9ac4c8_terseLabel_en-US" xlink:label="lab_us-gaap_MinorityInterestOwnershipPercentageByParent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Company ownership percentage of voting securities </link:label>

<link:label id="lab_us-gaap_MinorityInterestOwnershipPercentageByParent_label_en-US" xlink:label="lab_us-gaap_MinorityInterestOwnershipPercentageByParent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncontrolling Interest, Ownership Percentage by Parent </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByParent" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterestOwnershipPercentageByParent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MinorityInterestOwnershipPercentageByParent" xlink:to="lab_us-gaap_MinorityInterestOwnershipPercentageByParent" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_d15daaa1-45c9-4c7e-8035-5d55bb243b48_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2024 </link:label>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, to be Paid, Year Two </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:type="arc" order="1"/>

<link:label id="lab_good_LessorOperatingLeaseNumberofTenants_6586cd15-7cdb-48b2-b0a4-b2d64a2aa0cf_terseLabel_en-US" xlink:label="lab_good_LessorOperatingLeaseNumberofTenants" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of tenants </link:label>

<link:label id="lab_good_LessorOperatingLeaseNumberofTenants_label_en-US" xlink:label="lab_good_LessorOperatingLeaseNumberofTenants" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessor, Operating Lease, Number of Tenants </link:label>

<link:label id="lab_good_LessorOperatingLeaseNumberofTenants_documentation_en-US" xlink:label="lab_good_LessorOperatingLeaseNumberofTenants" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessor, Operating Lease, Number of Tenants </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_LessorOperatingLeaseNumberofTenants" xlink:href="good-20221231.xsd#good_LessorOperatingLeaseNumberofTenants"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_LessorOperatingLeaseNumberofTenants" xlink:to="lab_good_LessorOperatingLeaseNumberofTenants" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_UnrecognizedTaxBenefits_2ffc72cd-87e1-4bc4-8fbb-2a3ca2a92436_terseLabel_en-US" xlink:label="lab_us-gaap_UnrecognizedTaxBenefits" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Uncertain tax positions </link:label>

<link:label id="lab_us-gaap_UnrecognizedTaxBenefits_label_en-US" xlink:label="lab_us-gaap_UnrecognizedTaxBenefits" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unrecognized Tax Benefits </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefits" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_UnrecognizedTaxBenefits"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_UnrecognizedTaxBenefits" xlink:to="lab_us-gaap_UnrecognizedTaxBenefits" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter_0c55e3b6-bb00-41f1-bb05-452d6b3a79b9_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Thereafter </link:label>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessor, Operating Lease, Payment to be Received, after Year Five </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedMaturityTableTextBlock_2874437f-6aff-4f11-bf0e-867da61314c2_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedMaturityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Future Operating Lease Payments from Tenants under Non-Cancelable Leases </link:label>

<link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedMaturityTableTextBlock_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedMaturityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessor, Operating Lease, Payment to be Received, Fiscal Year Maturity [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedMaturityTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedMaturityTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedMaturityTableTextBlock" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedMaturityTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_GreenvilleSouthCarolinaIndustrialBuildingMember_bf34dec3-1749-40cd-a1a2-52a22e9c520b_terseLabel_en-US" xlink:label="lab_good_GreenvilleSouthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Greenville, South Carolina Industrial Building </link:label>

<link:label id="lab_good_GreenvilleSouthCarolinaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_GreenvilleSouthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Greenville, South Carolina Industrial Building [Member] </link:label>

<link:label id="lab_good_GreenvilleSouthCarolinaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_GreenvilleSouthCarolinaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Greenville, South Carolina Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_GreenvilleSouthCarolinaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_GreenvilleSouthCarolinaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_GreenvilleSouthCarolinaIndustrialBuildingMember" xlink:to="lab_good_GreenvilleSouthCarolinaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_95a551cd-a809-4070-b5e3-f7b6c46a2d67_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Future Lease Payments Due Under Operating Leases </link:label>

<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, Maturity [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityAddressAddressLine2_cdb21fdb-6c9c-4436-90b9-1db13f068b8a_terseLabel_en-US" xlink:label="lab_dei_EntityAddressAddressLine2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, Address Line Two </link:label>

<link:label id="lab_dei_EntityAddressAddressLine2_label_en-US" xlink:label="lab_dei_EntityAddressAddressLine2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, Address Line Two </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine2" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressAddressLine2"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityAddressAddressLine2" xlink:to="lab_dei_EntityAddressAddressLine2" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PaymentsToAcquireRealEstateHeldForInvestment_a6d5216c-54a8-48f7-8888-32a401b7ea35_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireRealEstateHeldForInvestment" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deposits on future acquisitions </link:label>

<link:label id="lab_us-gaap_PaymentsToAcquireRealEstateHeldForInvestment_label_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireRealEstateHeldForInvestment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments to Acquire Real Estate Held-for-investment </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireRealEstateHeldForInvestment" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsToAcquireRealEstateHeldForInvestment"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsToAcquireRealEstateHeldForInvestment" xlink:to="lab_us-gaap_PaymentsToAcquireRealEstateHeldForInvestment" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityAddressAddressLine1_78d06127-f86c-4906-9fbc-3dcfdeb184a5_terseLabel_en-US" xlink:label="lab_dei_EntityAddressAddressLine1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, Address Line One </link:label>

<link:label id="lab_dei_EntityAddressAddressLine1_label_en-US" xlink:label="lab_dei_EntityAddressAddressLine1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, Address Line One </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressAddressLine1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityAddressAddressLine1" xlink:to="lab_dei_EntityAddressAddressLine1" xlink:type="arc" order="1"/>

<link:label id="lab_good_PropertyHeldforsaleSellingCosts_2b6e1cdb-4591-4cb4-8b17-d78d2becfd9f_terseLabel_en-US" xlink:label="lab_good_PropertyHeldforsaleSellingCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate Sales Costs </link:label>

<link:label id="lab_good_PropertyHeldforsaleSellingCosts_label_en-US" xlink:label="lab_good_PropertyHeldforsaleSellingCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property Held-for-sale, Selling Costs </link:label>

<link:label id="lab_good_PropertyHeldforsaleSellingCosts_documentation_en-US" xlink:label="lab_good_PropertyHeldforsaleSellingCosts" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property Held-for-sale, Selling Costs </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PropertyHeldforsaleSellingCosts" xlink:href="good-20221231.xsd#good_PropertyHeldforsaleSellingCosts"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PropertyHeldforsaleSellingCosts" xlink:to="lab_good_PropertyHeldforsaleSellingCosts" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ClassOfStockDomain_c1e93d6d-4413-4dfe-8262-ce635bd31b1d_terseLabel_en-US" xlink:label="lab_us-gaap_ClassOfStockDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Class of Stock [Domain] </link:label>

<link:label id="lab_us-gaap_ClassOfStockDomain_label_en-US" xlink:label="lab_us-gaap_ClassOfStockDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Class of Stock [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ClassOfStockDomain" xlink:to="lab_us-gaap_ClassOfStockDomain" xlink:type="arc" order="1"/>

<link:label id="lab_good_EnglewoodColoradoOfficeBuildingMember_1507d736-f8d2-4a7e-9a85-c50535b9d252_terseLabel_en-US" xlink:label="lab_good_EnglewoodColoradoOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Englewood, Colorado Office Building </link:label>

<link:label id="lab_good_EnglewoodColoradoOfficeBuildingMember_label_en-US" xlink:label="lab_good_EnglewoodColoradoOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Englewood Colorado Office Building [Member] </link:label>

<link:label id="lab_good_EnglewoodColoradoOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_EnglewoodColoradoOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Englewood Colorado Office Building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_EnglewoodColoradoOfficeBuildingMember" xlink:href="good-20221231.xsd#good_EnglewoodColoradoOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_EnglewoodColoradoOfficeBuildingMember" xlink:to="lab_good_EnglewoodColoradoOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_InterestExpense_37f3daeb-472c-432b-9784-892dc5222344_negatedLabel_en-US" xlink:label="lab_us-gaap_InterestExpense" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest expense </link:label>

<link:label id="lab_us-gaap_InterestExpense_label_en-US" xlink:label="lab_us-gaap_InterestExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest Expense </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestExpense"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestExpense" xlink:to="lab_us-gaap_InterestExpense" xlink:type="arc" order="1"/>

<link:label id="lab_good_QuarterlyIncentiveFeePerAdvisoryAgreement_790c926a-cc45-4f8d-b8f5-14aecc6eb974_terseLabel_en-US" xlink:label="lab_good_QuarterlyIncentiveFeePerAdvisoryAgreement" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pre-incentive quarterly fee FFO in percentage of common stockholders' equity that will reward the adviser </link:label>

<link:label id="lab_good_QuarterlyIncentiveFeePerAdvisoryAgreement_label_en-US" xlink:label="lab_good_QuarterlyIncentiveFeePerAdvisoryAgreement" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Quarterly Incentive Fee Per Advisory Agreement </link:label>

<link:label id="lab_good_QuarterlyIncentiveFeePerAdvisoryAgreement_documentation_en-US" xlink:label="lab_good_QuarterlyIncentiveFeePerAdvisoryAgreement" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Quarterly incentive fee per advisory agreement. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_QuarterlyIncentiveFeePerAdvisoryAgreement" xlink:href="good-20221231.xsd#good_QuarterlyIncentiveFeePerAdvisoryAgreement"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_QuarterlyIncentiveFeePerAdvisoryAgreement" xlink:to="lab_good_QuarterlyIncentiveFeePerAdvisoryAgreement" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfSubsequentEventsTextBlock_e8955733-a826-4ed5-8493-c5aa57c01140_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfSubsequentEventsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Monthly Distributions Declared by Company's Board of Directors </link:label>

<link:label id="lab_us-gaap_ScheduleOfSubsequentEventsTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfSubsequentEventsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Subsequent Events [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSubsequentEventsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfSubsequentEventsTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfSubsequentEventsTextBlock" xlink:to="lab_us-gaap_ScheduleOfSubsequentEventsTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_PhiladelphiaPennsylvaniaIndustrialBuildingMember_af82b8d0-a574-4e1d-958d-02153e41b37b_terseLabel_en-US" xlink:label="lab_good_PhiladelphiaPennsylvaniaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Philadelphia Pennsylvania, Industrial Building </link:label>

<link:label id="lab_good_PhiladelphiaPennsylvaniaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_PhiladelphiaPennsylvaniaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Philadelphia Pennsylvania, Industrial Building [Member] </link:label>

<link:label id="lab_good_PhiladelphiaPennsylvaniaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_PhiladelphiaPennsylvaniaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Philadelphia Pennsylvania, Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PhiladelphiaPennsylvaniaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_PhiladelphiaPennsylvaniaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PhiladelphiaPennsylvaniaIndustrialBuildingMember" xlink:to="lab_good_PhiladelphiaPennsylvaniaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ScheduleOfDebtInstrumentsTextBlock_8fe212fc-db7d-4363-80ba-50e36c50f9eb_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Company's Mortgage Notes Payable and Credit Facility </link:label>

<link:label id="lab_us-gaap_ScheduleOfDebtInstrumentsTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Long-Term Debt Instruments [Table Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfDebtInstrumentsTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:to="lab_us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_NumberofPropertiesRepaidToCollateralizedMortgageNotesPayable_6e134959-a0f6-4923-ab4e-5c14b570fa99_terseLabel_en-US" xlink:label="lab_good_NumberofPropertiesRepaidToCollateralizedMortgageNotesPayable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of properties collateralized </link:label>

<link:label id="lab_good_NumberofPropertiesRepaidToCollateralizedMortgageNotesPayable_label_en-US" xlink:label="lab_good_NumberofPropertiesRepaidToCollateralizedMortgageNotesPayable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Properties Repaid To Collateralized Mortgage Notes Payable </link:label>

<link:label id="lab_good_NumberofPropertiesRepaidToCollateralizedMortgageNotesPayable_documentation_en-US" xlink:label="lab_good_NumberofPropertiesRepaidToCollateralizedMortgageNotesPayable" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Properties Repaid To Collateralized Mortgage Notes Payable </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NumberofPropertiesRepaidToCollateralizedMortgageNotesPayable" xlink:href="good-20221231.xsd#good_NumberofPropertiesRepaidToCollateralizedMortgageNotesPayable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NumberofPropertiesRepaidToCollateralizedMortgageNotesPayable" xlink:to="lab_good_NumberofPropertiesRepaidToCollateralizedMortgageNotesPayable" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_BuildingMember_c0175bb1-23c3-4941-b06c-18b1ccf1f73f_terseLabel_en-US" xlink:label="lab_us-gaap_BuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Building </link:label>

<link:label id="lab_us-gaap_BuildingMember_label_en-US" xlink:label="lab_us-gaap_BuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingMember" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BuildingMember" xlink:to="lab_us-gaap_BuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_SeniorCommonStockMember_bc510bc7-45f0-4ef0-99ee-7c2c512a73e8_terseLabel_en-US" xlink:label="lab_good_SeniorCommonStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior Common Stock </link:label>

<link:label id="lab_good_SeniorCommonStockMember_label_en-US" xlink:label="lab_good_SeniorCommonStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior Common Stock [Member] </link:label>

<link:label id="lab_good_SeniorCommonStockMember_documentation_en-US" xlink:label="lab_good_SeniorCommonStockMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior common stock. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_SeniorCommonStockMember" xlink:href="good-20221231.xsd#good_SeniorCommonStockMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_SeniorCommonStockMember" xlink:to="lab_good_SeniorCommonStockMember" xlink:type="arc" order="1"/>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationByPropertyTable_aecddb7d-8cdf-4947-bb7d-15623c772f08_terseLabel_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationByPropertyTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, by Property [Table] </link:label>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationByPropertyTable_label_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationByPropertyTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, by Property [Table] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationByPropertyTable" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RealEstateAndAccumulatedDepreciationByPropertyTable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationByPropertyTable" xlink:to="lab_srt_RealEstateAndAccumulatedDepreciationByPropertyTable" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StockRedeemedOrCalledDuringPeriodShares_bec7df06-726f-4fe8-a17d-d77bcab10451_verboseLabel_en-US" xlink:label="lab_us-gaap_StockRedeemedOrCalledDuringPeriodShares" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Redemptions of OP Units (in shares) </link:label>

<link:label id="lab_us-gaap_StockRedeemedOrCalledDuringPeriodShares_e20f7525-1d85-4628-a0c3-baa494006e0e_terseLabel_en-US" xlink:label="lab_us-gaap_StockRedeemedOrCalledDuringPeriodShares" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock redeemed (in shares) </link:label>

<link:label id="lab_us-gaap_StockRedeemedOrCalledDuringPeriodShares_label_en-US" xlink:label="lab_us-gaap_StockRedeemedOrCalledDuringPeriodShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Redeemed or Called During Period, Shares </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRedeemedOrCalledDuringPeriodShares" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockRedeemedOrCalledDuringPeriodShares"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockRedeemedOrCalledDuringPeriodShares" xlink:to="lab_us-gaap_StockRedeemedOrCalledDuringPeriodShares" xlink:type="arc" order="1"/>

<link:label id="lab_good_PittsburgPennsylvaniaIndustrialBuildingMember_404f44d4-7e4f-4cb1-9028-a50e8dedc7b6_terseLabel_en-US" xlink:label="lab_good_PittsburgPennsylvaniaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pittsburg, Pennsylvania Industrial Building </link:label>

<link:label id="lab_good_PittsburgPennsylvaniaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_PittsburgPennsylvaniaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pittsburg, Pennsylvania Industrial Building [Member] </link:label>

<link:label id="lab_good_PittsburgPennsylvaniaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_PittsburgPennsylvaniaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pittsburg, Pennsylvania Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PittsburgPennsylvaniaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_PittsburgPennsylvaniaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PittsburgPennsylvaniaIndustrialBuildingMember" xlink:to="lab_good_PittsburgPennsylvaniaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_ProceedsFromNotesPayable_47509057-3d82-4534-ac08-f945d07e6271_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromNotesPayable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Borrowings under mortgage notes payable </link:label>

<link:label id="lab_us-gaap_ProceedsFromNotesPayable_label_en-US" xlink:label="lab_us-gaap_ProceedsFromNotesPayable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from Notes Payable </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromNotesPayable" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromNotesPayable"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromNotesPayable" xlink:to="lab_us-gaap_ProceedsFromNotesPayable" xlink:type="arc" order="1"/>

<link:label id="lab_good_TerreHauteIndianaIndustrialBuildingMember_df3919ff-5c39-4a28-a7d4-79f3dbe89545_terseLabel_en-US" xlink:label="lab_good_TerreHauteIndianaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Terre Haute, Indiana Industrial Building </link:label>

<link:label id="lab_good_TerreHauteIndianaIndustrialBuildingMember_label_en-US" xlink:label="lab_good_TerreHauteIndianaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Terre Haute, Indiana Industrial Building [Member] </link:label>

<link:label id="lab_good_TerreHauteIndianaIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_TerreHauteIndianaIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Terre Haute, Indiana Industrial Building </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_TerreHauteIndianaIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_TerreHauteIndianaIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_TerreHauteIndianaIndustrialBuildingMember" xlink:to="lab_good_TerreHauteIndianaIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_NoncontrollingInterestOwnershipbyNoncontrollingOwnersNumberofShares_6e957acc-0aa4-4631-9c31-dd1f89a03953_terseLabel_en-US" xlink:label="lab_good_NoncontrollingInterestOwnershipbyNoncontrollingOwnersNumberofShares" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted average number of OP Units held by Non-controlling OP Unitholders (in shares) </link:label>

<link:label id="lab_good_NoncontrollingInterestOwnershipbyNoncontrollingOwnersNumberofShares_label_en-US" xlink:label="lab_good_NoncontrollingInterestOwnershipbyNoncontrollingOwnersNumberofShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncontrolling Interest, Ownership by Noncontrolling Owners, Number of Shares </link:label>

<link:label id="lab_good_NoncontrollingInterestOwnershipbyNoncontrollingOwnersNumberofShares_documentation_en-US" xlink:label="lab_good_NoncontrollingInterestOwnershipbyNoncontrollingOwnersNumberofShares" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncontrolling Interest, Ownership by Noncontrolling Owners, Number of Shares </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_NoncontrollingInterestOwnershipbyNoncontrollingOwnersNumberofShares" xlink:href="good-20221231.xsd#good_NoncontrollingInterestOwnershipbyNoncontrollingOwnersNumberofShares"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_NoncontrollingInterestOwnershipbyNoncontrollingOwnersNumberofShares" xlink:to="lab_good_NoncontrollingInterestOwnershipbyNoncontrollingOwnersNumberofShares" xlink:type="arc" order="1"/>

<link:label id="lab_good_AmountToBePaidToAdviserInPercentageOfPreIncentiveFeeConditionOne_7edba3e7-0886-427c-b218-7e131267cff2_terseLabel_en-US" xlink:label="lab_good_AmountToBePaidToAdviserInPercentageOfPreIncentiveFeeConditionOne" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amount to be paid to adviser in percentage of pre-incentive fee condition one </link:label>

<link:label id="lab_good_AmountToBePaidToAdviserInPercentageOfPreIncentiveFeeConditionOne_label_en-US" xlink:label="lab_good_AmountToBePaidToAdviserInPercentageOfPreIncentiveFeeConditionOne" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amount To Be Paid To Adviser In Percentage Of Pre Incentive Fee Condition One </link:label>

<link:label id="lab_good_AmountToBePaidToAdviserInPercentageOfPreIncentiveFeeConditionOne_documentation_en-US" xlink:label="lab_good_AmountToBePaidToAdviserInPercentageOfPreIncentiveFeeConditionOne" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amount to be paid to adviser in percentage of pre incentive fee condition one. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_AmountToBePaidToAdviserInPercentageOfPreIncentiveFeeConditionOne" xlink:href="good-20221231.xsd#good_AmountToBePaidToAdviserInPercentageOfPreIncentiveFeeConditionOne"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_AmountToBePaidToAdviserInPercentageOfPreIncentiveFeeConditionOne" xlink:to="lab_good_AmountToBePaidToAdviserInPercentageOfPreIncentiveFeeConditionOne" xlink:type="arc" order="1"/>

<link:label id="lab_good_PublicStockOfferingMember_f7d67be2-a6ba-46cb-8161-197b85b76637_terseLabel_en-US" xlink:label="lab_good_PublicStockOfferingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Public Stock Offering </link:label>

<link:label id="lab_good_PublicStockOfferingMember_label_en-US" xlink:label="lab_good_PublicStockOfferingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Public Stock Offering [Member] </link:label>

<link:label id="lab_good_PublicStockOfferingMember_documentation_en-US" xlink:label="lab_good_PublicStockOfferingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Public Stock Offering </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_PublicStockOfferingMember" xlink:href="good-20221231.xsd#good_PublicStockOfferingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_PublicStockOfferingMember" xlink:to="lab_good_PublicStockOfferingMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_CharlotteNorthCarolinaMember_457ffb9c-d0b7-462f-8915-81c37c4d3529_terseLabel_en-US" xlink:label="lab_good_CharlotteNorthCarolinaMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Charlotte, North Carolina </link:label>

<link:label id="lab_good_CharlotteNorthCarolinaMember_label_en-US" xlink:label="lab_good_CharlotteNorthCarolinaMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Charlotte, North Carolina [Member] </link:label>

<link:label id="lab_good_CharlotteNorthCarolinaMember_documentation_en-US" xlink:label="lab_good_CharlotteNorthCarolinaMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Charlotte, North Carolina </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_CharlotteNorthCarolinaMember" xlink:href="good-20221231.xsd#good_CharlotteNorthCarolinaMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_CharlotteNorthCarolinaMember" xlink:to="lab_good_CharlotteNorthCarolinaMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_RealEstateAndLeaseIntangiblesPolicyPolicyTextBlock_2d72ef76-16db-4cee-a4ca-92c57108de85_terseLabel_en-US" xlink:label="lab_good_RealEstateAndLeaseIntangiblesPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate and Lease Intangibles </link:label>

<link:label id="lab_good_RealEstateAndLeaseIntangiblesPolicyPolicyTextBlock_label_en-US" xlink:label="lab_good_RealEstateAndLeaseIntangiblesPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real Estate And Lease Intangibles Policy [Policy Text Block] </link:label>

<link:label id="lab_good_RealEstateAndLeaseIntangiblesPolicyPolicyTextBlock_documentation_en-US" xlink:label="lab_good_RealEstateAndLeaseIntangiblesPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real estate and lease intangibles. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_RealEstateAndLeaseIntangiblesPolicyPolicyTextBlock" xlink:href="good-20221231.xsd#good_RealEstateAndLeaseIntangiblesPolicyPolicyTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_RealEstateAndLeaseIntangiblesPolicyPolicyTextBlock" xlink:to="lab_good_RealEstateAndLeaseIntangiblesPolicyPolicyTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements_22cd86eb-eacf-4afd-9538-0572b61e01d4_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Buildings & improvements, initial cost </link:label>

<link:label id="lab_us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements_label_en-US" xlink:label="lab_us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements" xlink:to="lab_us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements" xlink:type="arc" order="1"/>

<link:label id="lab_good_DenverColoradoIndustrialBuildingMember_82739f76-9fe0-4a7f-8975-7fe66c1efa12_terseLabel_en-US" xlink:label="lab_good_DenverColoradoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Denver, Colorado Industrial Building </link:label>

<link:label id="lab_good_DenverColoradoIndustrialBuildingMember_label_en-US" xlink:label="lab_good_DenverColoradoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Denver, Colorado Industrial Building [Member] </link:label>

<link:label id="lab_good_DenverColoradoIndustrialBuildingMember_documentation_en-US" xlink:label="lab_good_DenverColoradoIndustrialBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Denver, Colorado Industrial Building [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DenverColoradoIndustrialBuildingMember" xlink:href="good-20221231.xsd#good_DenverColoradoIndustrialBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DenverColoradoIndustrialBuildingMember" xlink:to="lab_good_DenverColoradoIndustrialBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StraightLineRent_618f2c1f-af7d-4de3-99d6-9fb9a72c98be_negatedLabel_en-US" xlink:label="lab_us-gaap_StraightLineRent" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase in deferred rent receivable </link:label>

<link:label id="lab_us-gaap_StraightLineRent_label_en-US" xlink:label="lab_us-gaap_StraightLineRent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Straight Line Rent </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StraightLineRent" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StraightLineRent"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StraightLineRent" xlink:to="lab_us-gaap_StraightLineRent" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_29deee1b-b7a1-435a-85bb-bcde19561e1b_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2027 </link:label>

<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Asset, Expected Amortization, Year Five </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_PropertyPlantAndEquipmentImpairment_df33bc9c-c4a4-462a-9d57-48d25e9bff6c_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentImpairment" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Impairment Charges </link:label>

<link:label id="lab_us-gaap_PropertyPlantAndEquipmentImpairment_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentImpairment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment, Impairment [Policy Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentImpairment" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentImpairment"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentImpairment" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentImpairment" xlink:type="arc" order="1"/>

<link:label id="lab_good_DartmouthMassachusettsRetailLocationMember_9c0d7305-c360-4cd3-830b-2a526d7127fc_terseLabel_en-US" xlink:label="lab_good_DartmouthMassachusettsRetailLocationMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dartmouth, Massachusetts Retail Location </link:label>

<link:label id="lab_good_DartmouthMassachusettsRetailLocationMember_label_en-US" xlink:label="lab_good_DartmouthMassachusettsRetailLocationMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dartmouth Massachusetts Retail Location [Member] </link:label>

<link:label id="lab_good_DartmouthMassachusettsRetailLocationMember_documentation_en-US" xlink:label="lab_good_DartmouthMassachusettsRetailLocationMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dartmouth Massachusetts retail location. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DartmouthMassachusettsRetailLocationMember" xlink:href="good-20221231.xsd#good_DartmouthMassachusettsRetailLocationMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DartmouthMassachusettsRetailLocationMember" xlink:to="lab_good_DartmouthMassachusettsRetailLocationMember" xlink:type="arc" order="1"/>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_47aed971-1d98-46f8-997e-912f6c2bcdd9_terseLabel_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Name of Property [Axis] </link:label>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_label_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Name of Property [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis" xlink:to="lab_srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis" xlink:type="arc" order="1"/>

<link:label id="lab_good_MortgageNotesPayableMember_911a1a25-7025-484f-8b90-2ea1486175ab_terseLabel_en-US" xlink:label="lab_good_MortgageNotesPayableMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Mortgage notes payable </link:label>

<link:label id="lab_good_MortgageNotesPayableMember_label_en-US" xlink:label="lab_good_MortgageNotesPayableMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Mortgage Notes Payable [Member] </link:label>

<link:label id="lab_good_MortgageNotesPayableMember_documentation_en-US" xlink:label="lab_good_MortgageNotesPayableMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Mortgage notes payable. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_MortgageNotesPayableMember" xlink:href="good-20221231.xsd#good_MortgageNotesPayableMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_MortgageNotesPayableMember" xlink:to="lab_good_MortgageNotesPayableMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_A2019RegistrationStatementMember_3dd5644a-938c-4cd2-b6fd-6690637b3cff_terseLabel_en-US" xlink:label="lab_good_A2019RegistrationStatementMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2019 Registration Statement </link:label>

<link:label id="lab_good_A2019RegistrationStatementMember_label_en-US" xlink:label="lab_good_A2019RegistrationStatementMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2019 Registration Statement [Member] </link:label>

<link:label id="lab_good_A2019RegistrationStatementMember_documentation_en-US" xlink:label="lab_good_A2019RegistrationStatementMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2019 Registration Statement </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_A2019RegistrationStatementMember" xlink:href="good-20221231.xsd#good_A2019RegistrationStatementMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_A2019RegistrationStatementMember" xlink:to="lab_good_A2019RegistrationStatementMember" xlink:type="arc" order="1"/>

<link:label id="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyNet_c0d75a2b-db6d-4f3d-beb5-1a4ea61e1b53_terseLabel_en-US" xlink:label="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total real estate held for sale </link:label>

<link:label id="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyNet_label_en-US" xlink:label="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Group Including Discontinued Operation Real Estate Investment Property Net </link:label>

<link:label id="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyNet_documentation_en-US" xlink:label="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyNet" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal group including discontinued operation real estate investment property net. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyNet" xlink:href="good-20221231.xsd#good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyNet"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyNet" xlink:to="lab_good_DisposalGroupIncludingDiscontinuedOperationRealEstateInvestmentPropertyNet" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RealEstateImprovements_7ec46e5a-0f3d-42e0-9566-e409cf98c2de_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstateImprovements" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Improvements </link:label>

<link:label id="lab_us-gaap_RealEstateImprovements_label_en-US" xlink:label="lab_us-gaap_RealEstateImprovements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Improvements </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateImprovements" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RealEstateImprovements"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstateImprovements" xlink:to="lab_us-gaap_RealEstateImprovements" xlink:type="arc" order="1"/>

<link:label id="lab_dei_EntityIncorporationDateOfIncorporation_5515f13c-a24c-4738-8b52-3e64c69e5c0a_terseLabel_en-US" xlink:label="lab_dei_EntityIncorporationDateOfIncorporation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Subsidiary and business trust of the Company, formed under the laws of the Commonwealth of Massachusetts, date </link:label>

<link:label id="lab_dei_EntityIncorporationDateOfIncorporation_label_en-US" xlink:label="lab_dei_EntityIncorporationDateOfIncorporation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Incorporation, Date of Incorporation </link:label>

<link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationDateOfIncorporation" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityIncorporationDateOfIncorporation"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityIncorporationDateOfIncorporation" xlink:to="lab_dei_EntityIncorporationDateOfIncorporation" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_GeneralAndAdministrativeExpense_253d609f-92b1-473b-8eae-ddc00bd8033a_terseLabel_en-US" xlink:label="lab_us-gaap_GeneralAndAdministrativeExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> General and administrative </link:label>

<link:label id="lab_us-gaap_GeneralAndAdministrativeExpense_label_en-US" xlink:label="lab_us-gaap_GeneralAndAdministrativeExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> General and Administrative Expense </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GeneralAndAdministrativeExpense"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GeneralAndAdministrativeExpense" xlink:to="lab_us-gaap_GeneralAndAdministrativeExpense" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1_429be337-a1a2-4370-8c62-a4590f491beb_terseLabel_en-US" xlink:label="lab_us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate Fixed Rate Debt Issued </link:label>

<link:label id="lab_us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1_label_en-US" xlink:label="lab_us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncash or Part Noncash Acquisition, Debt Assumed </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1" xlink:to="lab_us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_LongtermDebtTypeDomain_bd225d7d-6a69-4e19-932c-dddff9fe4864_terseLabel_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term Debt, Type [Domain] </link:label>

<link:label id="lab_us-gaap_LongtermDebtTypeDomain_label_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Type [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongtermDebtTypeDomain" xlink:to="lab_us-gaap_LongtermDebtTypeDomain" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_OtherCommitmentsLineItems_c4ceeaac-1cf4-4b28-b46e-d89658fc4a51_terseLabel_en-US" xlink:label="lab_us-gaap_OtherCommitmentsLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Commitments [Line Items] </link:label>

<link:label id="lab_us-gaap_OtherCommitmentsLineItems_label_en-US" xlink:label="lab_us-gaap_OtherCommitmentsLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Commitments [Line Items] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherCommitmentsLineItems"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherCommitmentsLineItems" xlink:to="lab_us-gaap_OtherCommitmentsLineItems" xlink:type="arc" order="1"/>

<link:label id="lab_good_DealerManagementFeePaymentsForCommissions_771b86b5-8a09-438e-bf78-e7114b5449bc_terseLabel_en-US" xlink:label="lab_good_DealerManagementFeePaymentsForCommissions" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments for commissions </link:label>

<link:label id="lab_good_DealerManagementFeePaymentsForCommissions_label_en-US" xlink:label="lab_good_DealerManagementFeePaymentsForCommissions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dealer Management Fee, Payments For Commissions </link:label>

<link:label id="lab_good_DealerManagementFeePaymentsForCommissions_documentation_en-US" xlink:label="lab_good_DealerManagementFeePaymentsForCommissions" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dealer Management Fee, Payments For Commissions </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DealerManagementFeePaymentsForCommissions" xlink:href="good-20221231.xsd#good_DealerManagementFeePaymentsForCommissions"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DealerManagementFeePaymentsForCommissions" xlink:to="lab_good_DealerManagementFeePaymentsForCommissions" xlink:type="arc" order="1"/>

<link:label id="lab_good_MasonOhioOfficeBuildingMember_7b859ef4-1d63-4bca-8a16-b72f40f80f3d_terseLabel_en-US" xlink:label="lab_good_MasonOhioOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Mason, Ohio Office Building </link:label>

<link:label id="lab_good_MasonOhioOfficeBuildingMember_label_en-US" xlink:label="lab_good_MasonOhioOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Mason Ohio Office Building [Member] </link:label>

<link:label id="lab_good_MasonOhioOfficeBuildingMember_documentation_en-US" xlink:label="lab_good_MasonOhioOfficeBuildingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Mason Ohio office building. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_MasonOhioOfficeBuildingMember" xlink:href="good-20221231.xsd#good_MasonOhioOfficeBuildingMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_MasonOhioOfficeBuildingMember" xlink:to="lab_good_MasonOhioOfficeBuildingMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_StatementOfStockholdersEquityAbstract_bf3ec27c-7ce9-4ab3-bd96-3ea63328b2d2_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement of Stockholders' Equity [Abstract] </link:label>

<link:label id="lab_us-gaap_StatementOfStockholdersEquityAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement of Stockholders' Equity [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfStockholdersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementOfStockholdersEquityAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="lab_us-gaap_StatementOfStockholdersEquityAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DividendsAxis_295a84e8-2b12-46af-a89f-cf29ac53a868_terseLabel_en-US" xlink:label="lab_us-gaap_DividendsAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividends [Axis] </link:label>

<link:label id="lab_us-gaap_DividendsAxis_label_en-US" xlink:label="lab_us-gaap_DividendsAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dividends [Axis] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DividendsAxis"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DividendsAxis" xlink:to="lab_us-gaap_DividendsAxis" xlink:type="arc" order="1"/>

<link:label id="lab_good_LandSubjecttoLandLeaseAgreementsValue_de900024-b8e6-47aa-a777-5ff0fc90cb47_terseLabel_en-US" xlink:label="lab_good_LandSubjecttoLandLeaseAgreementsValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Land value subject to land lease agreements </link:label>

<link:label id="lab_good_LandSubjecttoLandLeaseAgreementsValue_label_en-US" xlink:label="lab_good_LandSubjecttoLandLeaseAgreementsValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Land Subject to Land Lease Agreements, Value </link:label>

<link:label id="lab_good_LandSubjecttoLandLeaseAgreementsValue_documentation_en-US" xlink:label="lab_good_LandSubjecttoLandLeaseAgreementsValue" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Land Subject to Land Lease Agreements, Value </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_LandSubjecttoLandLeaseAgreementsValue" xlink:href="good-20221231.xsd#good_LandSubjecttoLandLeaseAgreementsValue"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_LandSubjecttoLandLeaseAgreementsValue" xlink:to="lab_good_LandSubjecttoLandLeaseAgreementsValue" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_81128c5d-421f-42b1-8068-d9b4fe0f3c18_terseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash flows from financing activities: </link:label>

<link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Cash Provided by (Used in) Financing Activities [Abstract] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationDisclosureTextBlock_c4fedc9e-a050-41bd-b5f6-cc5d945c6319_terseLabel_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SCHEDULE III—REAL ESTATE AND ACCUMULATED DEPRECIATION </link:label>

<link:label id="lab_srt_RealEstateAndAccumulatedDepreciationDisclosureTextBlock_label_en-US" xlink:label="lab_srt_RealEstateAndAccumulatedDepreciationDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Text Block] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_srt_RealEstateAndAccumulatedDepreciationDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RealEstateAndAccumulatedDepreciationDisclosureTextBlock"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RealEstateAndAccumulatedDepreciationDisclosureTextBlock" xlink:to="lab_srt_RealEstateAndAccumulatedDepreciationDisclosureTextBlock" xlink:type="arc" order="1"/>

<link:label id="lab_good_DeductionsAbstract_2d5d3cec-ff77-444a-b03d-8dc603e54353_terseLabel_en-US" xlink:label="lab_good_DeductionsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deductions: </link:label>

<link:label id="lab_good_DeductionsAbstract_label_en-US" xlink:label="lab_good_DeductionsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deductions [Abstract] </link:label>

<link:label id="lab_good_DeductionsAbstract_documentation_en-US" xlink:label="lab_good_DeductionsAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deductions. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_DeductionsAbstract" xlink:href="good-20221231.xsd#good_DeductionsAbstract"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_DeductionsAbstract" xlink:to="lab_good_DeductionsAbstract" xlink:type="arc" order="1"/>

<link:label id="lab_good_ReceiptsFromTenantsForReserves_08363bec-7a8e-445d-a4e5-f9e1908fe694_terseLabel_en-US" xlink:label="lab_good_ReceiptsFromTenantsForReserves" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Receipts from tenants for reserves </link:label>

<link:label id="lab_good_ReceiptsFromTenantsForReserves_label_en-US" xlink:label="lab_good_ReceiptsFromTenantsForReserves" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Receipts From Tenants For Reserves </link:label>

<link:label id="lab_good_ReceiptsFromTenantsForReserves_documentation_en-US" xlink:label="lab_good_ReceiptsFromTenantsForReserves" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Receipts from tenants for reserves. </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_ReceiptsFromTenantsForReserves" xlink:href="good-20221231.xsd#good_ReceiptsFromTenantsForReserves"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_ReceiptsFromTenantsForReserves" xlink:to="lab_good_ReceiptsFromTenantsForReserves" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_DisposalGroupClassificationDomain_e791f18a-42f5-48ae-a163-c982a36467af_terseLabel_en-US" xlink:label="lab_us-gaap_DisposalGroupClassificationDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Group Classification [Domain] </link:label>

<link:label id="lab_us-gaap_DisposalGroupClassificationDomain_label_en-US" xlink:label="lab_us-gaap_DisposalGroupClassificationDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disposal Group Classification [Domain] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisposalGroupClassificationDomain"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain" xlink:to="lab_us-gaap_DisposalGroupClassificationDomain" xlink:type="arc" order="1"/>

<link:label id="lab_good_GladstoneCommercialLimitedPartnershipMember_8f16eb30-7e4b-4fce-b997-7d8da9aa7440_terseLabel_en-US" xlink:label="lab_good_GladstoneCommercialLimitedPartnershipMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Partnership </link:label>

<link:label id="lab_good_GladstoneCommercialLimitedPartnershipMember_label_en-US" xlink:label="lab_good_GladstoneCommercialLimitedPartnershipMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gladstone Commercial Limited Partnership [Member] </link:label>

<link:label id="lab_good_GladstoneCommercialLimitedPartnershipMember_documentation_en-US" xlink:label="lab_good_GladstoneCommercialLimitedPartnershipMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gladstone Commercial Limited Partnership [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_GladstoneCommercialLimitedPartnershipMember" xlink:href="good-20221231.xsd#good_GladstoneCommercialLimitedPartnershipMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_GladstoneCommercialLimitedPartnershipMember" xlink:to="lab_good_GladstoneCommercialLimitedPartnershipMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_AssetImpairmentCharges_a4372657-386e-4b67-b7e6-1c05195d422e_terseLabel_en-US" xlink:label="lab_us-gaap_AssetImpairmentCharges" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Impairment charge </link:label>

<link:label id="lab_us-gaap_AssetImpairmentCharges_b8f8914a-f7f8-4791-b3fd-d21eb5322e78_verboseLabel_en-US" xlink:label="lab_us-gaap_AssetImpairmentCharges" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate Impairment Charge for the Twelve Months Ended December 31, 2022 </link:label>

<link:label id="lab_us-gaap_AssetImpairmentCharges_label_en-US" xlink:label="lab_us-gaap_AssetImpairmentCharges" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset Impairment Charges </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetImpairmentCharges" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetImpairmentCharges"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetImpairmentCharges" xlink:to="lab_us-gaap_AssetImpairmentCharges" xlink:type="arc" order="1"/>

<link:label id="lab_good_OcalaFloridaIndustrialBuildingTwoMember_d5e25553-19e1-45d2-be6d-1e6db83d7a60_terseLabel_en-US" xlink:label="lab_good_OcalaFloridaIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ocala, Florida Industrial Building Two </link:label>

<link:label id="lab_good_OcalaFloridaIndustrialBuildingTwoMember_label_en-US" xlink:label="lab_good_OcalaFloridaIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ocala, Florida Industrial Building Two [Member] </link:label>

<link:label id="lab_good_OcalaFloridaIndustrialBuildingTwoMember_documentation_en-US" xlink:label="lab_good_OcalaFloridaIndustrialBuildingTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ocala, Florida Industrial Building Two [Member] </link:label>

<link:loc xlink:type="locator" xlink:label="loc_good_OcalaFloridaIndustrialBuildingTwoMember" xlink:href="good-20221231.xsd#good_OcalaFloridaIndustrialBuildingTwoMember"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_good_OcalaFloridaIndustrialBuildingTwoMember" xlink:to="lab_good_OcalaFloridaIndustrialBuildingTwoMember" xlink:type="arc" order="1"/>

<link:label id="lab_us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount_2f7c2a2a-a099-4f78-945a-64c07b665148_terseLabel_en-US" xlink:label="lab_us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Mezzanine Equity </link:label>

<link:label id="lab_us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount_label_en-US" xlink:label="lab_us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount </link:label>

<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount"/>

<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount" xlink:to="lab_us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount" xlink:type="arc" order="1"/>

</link:labelLink>

</link:linkbase>

3 Subsequent Filings that Reference this Filing

  As Of               Filer                 Filing    For·On·As Docs:Size             Issuer                      Filing Agent

 2/21/24  Gladstone Commercial Corp.        10-K       12/31/23   91:16M
 5/03/23  Gladstone Commercial Corp.        10-Q        3/31/23   63:7.2M
 3/03/23  Gladstone Commercial Corp.        424B5                  2:625K                                   Donnelley … Solutions/FA

18 Previous Filings that this Filing References

  As Of               Filer                 Filing    For·On·As Docs:Size             Issuer                      Filing Agent

 2/09/23  Gladstone Commercial Corp.        8-K:1,9     2/09/23   14:276K                                   Donnelley … Solutions/FA
11/23/22  Gladstone Commercial Corp.        S-3ASR     11/23/22    7:1M                                     Donnelley … Solutions/FA
 8/19/22  Gladstone Commercial Corp.        8-K:1,2,9   8/18/22   13:2.9M                                   Donnelley … Solutions/FA
 8/09/21  Gladstone Commercial Corp.        10-Q        6/30/21   69:8.9M
 6/24/21  Gladstone Commercial Corp.        8-K:1,3,5,7 6/21/21   18:1.4M                                   Donnelley … Solutions/FA
 2/16/21  Gladstone Commercial Corp.        10-K       12/31/20   84:85M
 7/27/20  Gladstone Commercial Corp.        10-Q        6/30/20   71:12M
 2/20/20  Gladstone Commercial Corp.        8-K:1,3,5,7 2/20/20    9:1.1M                                   Donnelley … Solutions/FA
12/03/19  Gladstone Commercial Corp.        8-K:1,5,8,912/02/19    8:495K                                   Donnelley … Solutions/FA
 9/27/19  Gladstone Commercial Corp.        8-K:1,3,5,9 9/25/19    7:1M                                     Donnelley … Solutions/FA
 7/11/18  Gladstone Commercial Corp.        8-K:1,9     7/11/18    2:549K                                   Donnelley … Solutions/FA
 4/12/18  Gladstone Commercial Corp.        8-K:5,9     4/11/18    3:58K                                    Donnelley … Solutions/FA
 1/12/17  Gladstone Commercial Corp.        8-K:1,5,9   1/10/17    5:255K                                   Donnelley … Solutions/FA
12/01/16  Gladstone Commercial Corp.        8-K:1,5,7,911/29/16    6:124K                                   Donnelley … Solutions/FA
 7/10/07  Gladstone Commercial Corp.        8-K:5,9     7/10/07    3:23K                                    Donnelley Fi… Express/FA
 1/03/07  Gladstone Commercial Corp.        8-K:1,9     1/03/07    4:794K                                   Bowne - DC/FA
 8/08/03  Gladstone Commercial Corp.        S-11/A                 6:769K                                   Bowne - DC/FA
 6/11/03  Gladstone Commercial Corp.        S-11                  10:820K                                   Bowne - DC/FA

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Filing Submission 0001234006-23-000003 – Alternative Formats (Word / Rich Text, HTML, Plain Text, et al.)