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OncoCyte Corp – ‘10-K’ for 12/31/19 – ‘EX-101.LAB’

On:  Wednesday, 3/25/20, at 5:34pm ET   ·   As of:  3/26/20   ·   For:  12/31/19   ·   Accession #:  1493152-20-4738   ·   File #:  1-37648

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

 3/26/20  OncoCyte Corp                     10-K       12/31/19   77:37M                                    M2 Compliance/FA

Annual Report   —   Form 10-K   —   Sect. 13 / 15(d) – SEA’34
Filing Table of Contents

Document/Exhibit                   Description                      Pages   Size 

 1: 10-K        Annual Report                                       HTML    697K 
 2: EX-4.11     Instrument Defining the Rights of Security Holders  HTML     24K 
 3: EX-10.10    Material Contract                                   HTML     31K 
 4: EX-10.24    Material Contract                                   HTML     32K 
 5: EX-10.34    Material Contract                                   HTML     35K 
 6: EX-10.35    Material Contract                                   HTML     50K 
 7: EX-10.36    Material Contract                                   HTML     97K 
 8: EX-21       Subsidiaries List                                   HTML     22K 
 9: EX-23.1     Consent of Experts or Counsel                       HTML     24K 
10: EX-31       Certification -- §302 - SOA'02                      HTML     37K 
11: EX-32       Certification -- §906 - SOA'02                      HTML     25K 
23: R1          Document and Entity Information                     HTML     61K 
60: R2          Balance Sheets                                      HTML     97K 
67: R3          Balance Sheets (Parenthetical)                      HTML     43K 
49: R4          Statements of Operations                            HTML     63K 
24: R5          Statements of Comprehensive Loss                    HTML     35K 
61: R6          Statements of Shareholders' Equity                  HTML     66K 
68: R7          Statements of Cash Flows                            HTML    133K 
47: R8          Organization, Description of the Business and       HTML     37K 
                Liquidity                                                        
26: R9          Summary of Significant Accounting Policies          HTML     80K 
58: R10         Selected Balance Sheet Components                   HTML     41K 
70: R11         Related Party Transactions                          HTML     40K 
46: R12         Equity Method Investment in Razor Genomics, Inc.    HTML     45K 
25: R13         Loan Payable to Silicon Valley Bank                 HTML     44K 
59: R14         Shareholders' Equity                                HTML     32K 
71: R15         Stock-Based Compensation                            HTML     72K 
48: R16         Income Taxes                                        HTML     50K 
27: R17         Commitments and Contingencies                       HTML     66K 
62: R18         Subsequent Events                                   HTML     35K 
69: R19         Summary of Significant Accounting Policies          HTML    136K 
                (Policies)                                                       
35: R20         Summary of Significant Accounting Policies          HTML     34K 
                (Tables)                                                         
28: R21         Selected Balance Sheet Components (Tables)          HTML     47K 
52: R22         Related Party Transactions (Tables)                 HTML     28K 
74: R23         Equity Method Investment in Razor Genomics, Inc.    HTML     29K 
                (Tables)                                                         
36: R24         Loan Payable to Silicon Valley Bank (Tables)        HTML     29K 
29: R25         Stock-Based Compensation (Tables)                   HTML     70K 
53: R26         Income Taxes (Tables)                               HTML     47K 
75: R27         Commitments and Contingencies (Tables)              HTML     44K 
34: R28         Organization, Description of the Business and       HTML     52K 
                Liquidity (Details Narrative)                                    
30: R29         Summary of Significant Accounting Policies          HTML     81K 
                (Details Narrative)                                              
22: R30         Summary of Significant Accounting Policies -        HTML     33K 
                Schedule of Reconciliation of Cash, Cash                         
                Equivalents, and Restricted Cash (Details)                       
44: R31         Summary of Significant Accounting Policies -        HTML     31K 
                Common Stock Equivalents Excluded from Computation               
                of Diluted Net Loss Per Share of Common Stock                    
                (Details)                                                        
73: R32         Selected Balance Sheet Components (Details          HTML     32K 
                Narrative)                                                       
64: R33         Selected Balance Sheet Components - Schedule of     HTML     34K 
                Prepaid Expenses and Other Current Assets                        
                (Details)                                                        
21: R34         Selected Balance Sheet Components - Schedule of     HTML     31K 
                Deposits and Other Noncurrent Assets (Details)                   
43: R35         Selected Balance Sheet Components - Schedule of     HTML     30K 
                Accrued Expenses and Other Current Liabilities                   
                (Details)                                                        
72: R36         Selected Balance Sheet Components - Schedule of     HTML     36K 
                Right of Use Assets, Machinery and Equipment, Net                
                (Details)                                                        
63: R37         Related Party Transactions (Details Narrative)      HTML     99K 
20: R38         Related Party Transactions - Schedule of Aggregate  HTML     36K 
                Use of Fees Charged (Details)                                    
45: R39         Equity Method Investment in Razor Genomics, Inc.    HTML     80K 
                (Details Narrative)                                              
33: R40         Equity Method Investment in Razor Genomics, Inc. -  HTML     53K 
                Schedule of Condensed Balance Sheet Information                  
                (Details)                                                        
39: R41         Loan Payable to Silicon Valley Bank (Details        HTML    106K 
                Narrative)                                                       
77: R42         Loan Payable to Silicon Valley Bank - Schedule of   HTML     45K 
                Future Cash Payments of Loan Payable (Details)                   
55: R43         Shareholders' Equity (Details Narrative)            HTML     62K 
32: R44         Stock-Based Compensation (Details Narrative)        HTML     76K 
38: R45         Stock-Based Compensation - Summary of Stock Option  HTML     90K 
                Activity (Details)                                               
76: R46         Stock-Based Compensation - Schdule of Stock         HTML     46K 
                Options Outstanding, Vested and Exercisable                      
                (Details)                                                        
54: R47         Stock-Based Compensation - Summary of Stock-based   HTML     31K 
                Compensation Expense (Details)                                   
31: R48         Stock-Based Compensation - Schedule of Assumptions  HTML     35K 
                Used to Calculate Fair Value of Stock Options                    
                (Details)                                                        
40: R49         Income Taxes (Details Narrative)                    HTML     55K 
41: R50         Income Taxes - Schedule of Components of Deferred   HTML     50K 
                Tax Assets and Liabilities (Details)                             
18: R51         Income Taxes - Schedule of Income Tax               HTML     49K 
                Reconciliation (Details)                                         
56: R52         Income Taxes - Schedule of Unrecognized Tax         HTML     31K 
                Benefit (Details)                                                
65: R53         Commitments and Contingencies (Details Narrative)   HTML     67K 
42: R54         Commitments and Contingencies - Schedule of         HTML     31K 
                Supplemental Cash Flow Information Related to                    
                Operating and Financing Lease (Details)                          
19: R55         Commitments and Contingencies - Schedule of         HTML     45K 
                Supplemental Balance Sheet Information Related to                
                Operating and Financing Leases (Details)                         
57: R56         Commitments and Contingencies - Schedule of Future  HTML     70K 
                Minimum Lease Commitments for Operating and                      
                Financing Leases (Details)                                       
66: R57         Subsequent Events (Details Narrative)               HTML     71K 
37: XML         IDEA XML File -- Filing Summary                      XML    131K 
50: EXCEL       IDEA Workbook of Financial Reports                  XLSX     96K 
12: EX-101.INS  XBRL Instance -- ocx-20191231                        XML   1.15M 
14: EX-101.CAL  XBRL Calculations -- ocx-20191231_cal                XML    197K 
15: EX-101.DEF  XBRL Definitions -- ocx-20191231_def                 XML    614K 
16: EX-101.LAB  XBRL Labels -- ocx-20191231_lab                      XML   1.15M 
17: EX-101.PRE  XBRL Presentations -- ocx-20191231_pre               XML    855K 
13: EX-101.SCH  XBRL Schema -- ocx-20191231                          XSD    194K 
51: ZIP         XBRL Zipped Folder -- 0001493152-20-004738-xbrl      Zip    166K

‘EX-101.LAB’   —   XBRL Labels — ocx-20191231_lab

This Exhibit is an XBRL XML File.

                                                                                                                                                                                
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<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ParentCompanyMember" xlink:label="srt_ParentCompanyMember"/>
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<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ParentCompanyMember_lbl" xml:lang="en-US"> Lineage Cell Therapeutics, Inc [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
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<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_lbl" xml:lang="en-US"> Antidilutive Securities [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_StockOptionsMember" xlink:label="OCX_StockOptionsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_StockOptionsMember" xlink:to="OCX_StockOptionsMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_StockOptionsMember_lbl" xml:lang="en-US"> Stock Options [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_WarrantMember" xlink:label="us-gaap_WarrantMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WarrantMember" xlink:to="us-gaap_WarrantMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WarrantMember_lbl" xml:lang="en-US"> Warrants [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="us-gaap_BalanceSheetLocationAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BalanceSheetLocationAxis" xlink:to="us-gaap_BalanceSheetLocationAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BalanceSheetLocationAxis_lbl" xml:lang="en-US"> Balance Sheet Location [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_CurrentLiabilitiesMember" xlink:label="OCX_CurrentLiabilitiesMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_CurrentLiabilitiesMember" xlink:to="OCX_CurrentLiabilitiesMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_CurrentLiabilitiesMember_lbl" xml:lang="en-US"> Current Liabilities [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="us-gaap_DebtInstrumentAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xml:lang="en-US"> Debt Instrument [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_LoanAndSecurityAgreementMember" xlink:label="OCX_LoanAndSecurityAgreementMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LoanAndSecurityAgreementMember" xlink:to="OCX_LoanAndSecurityAgreementMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_LoanAndSecurityAgreementMember_lbl" xml:lang="en-US"> Loan and Security Agreement [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RangeAxis" xlink:to="srt_RangeAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_RangeAxis_lbl" xml:lang="en-US"> Range [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember"/>
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<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfWarrantOrRightAxis" xlink:label="us-gaap_ClassOfWarrantOrRightAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightAxis" xlink:to="us-gaap_ClassOfWarrantOrRightAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ClassOfWarrantOrRightAxis_lbl" xml:lang="en-US"> Class of Warrant or Right [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="us-gaap_PlanNameAxis"/>
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<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PlanNameAxis_lbl" xml:lang="en-US"> Plan Name [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_TwoThousandTenStockOptionPlanMember" xlink:label="OCX_TwoThousandTenStockOptionPlanMember"/>
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<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_TwoThousandTenStockOptionPlanMember_lbl" xml:lang="en-US"> 2010 Stock Option Plan [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis"/>
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<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AwardTypeAxis_lbl" xml:lang="en-US"> Award Type [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="us-gaap_EmployeeStockOptionMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeStockOptionMember" xlink:to="us-gaap_EmployeeStockOptionMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeStockOptionMember_lbl" xml:lang="en-US"> Stock Option Plan [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="us-gaap_IncomeStatementLocationAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementLocationAxis" xlink:to="us-gaap_IncomeStatementLocationAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeStatementLocationAxis_lbl" xml:lang="en-US"> Income Statement Location [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ResearchAndDevelopmentExpenseMember" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ResearchAndDevelopmentExpenseMember" xlink:to="us-gaap_ResearchAndDevelopmentExpenseMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember_lbl" xml:lang="en-US"> Research and Development [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpensesMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:to="us-gaap_SellingGeneralAndAdministrativeExpensesMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpensesMember_lbl" xml:lang="en-US"> General and Administrative [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SellingAndMarketingExpenseMember" xlink:label="us-gaap_SellingAndMarketingExpenseMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SellingAndMarketingExpenseMember" xlink:to="us-gaap_SellingAndMarketingExpenseMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SellingAndMarketingExpenseMember_lbl" xml:lang="en-US"> Sales and Marketing [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TypeOfArrangementAxis" xlink:to="us-gaap_TypeOfArrangementAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TypeOfArrangementAxis_lbl" xml:lang="en-US"> Type of Arrangement and Non-arrangement Transactions [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_SecuritiesPurchaseAgreementMember" xlink:label="OCX_SecuritiesPurchaseAgreementMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SecuritiesPurchaseAgreementMember" xlink:to="OCX_SecuritiesPurchaseAgreementMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_SecuritiesPurchaseAgreementMember_lbl" xml:lang="en-US"> Securities Purchase Agreement [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_TitleOfIndividualAxis" xlink:label="srt_TitleOfIndividualAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_TitleOfIndividualAxis" xlink:to="srt_TitleOfIndividualAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_TitleOfIndividualAxis_lbl" xml:lang="en-US"> Title of Individual [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_TwoAccreditedInvestorsMember" xlink:label="OCX_TwoAccreditedInvestorsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_TwoAccreditedInvestorsMember" xlink:to="OCX_TwoAccreditedInvestorsMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_TwoAccreditedInvestorsMember_lbl" xml:lang="en-US"> Two Accredited Investors [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_lbl" xml:lang="en-US"> Sale of Stock [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PrivatePlacementMember" xlink:label="us-gaap_PrivatePlacementMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrivatePlacementMember" xlink:to="us-gaap_PrivatePlacementMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PrivatePlacementMember_lbl" xml:lang="en-US"> Private Placement [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_StatementEquityComponentsAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl" xml:lang="en-US"> Equity Components [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockMember" xlink:to="us-gaap_CommonStockMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockMember_lbl" xml:lang="en-US"> Common Stock [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_TwoThousandTenPalnActivityMember" xlink:label="OCX_TwoThousandTenPalnActivityMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_TwoThousandTenPalnActivityMember" xlink:to="OCX_TwoThousandTenPalnActivityMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_TwoThousandTenPalnActivityMember_lbl" xml:lang="en-US"> 2010 Plan Activity [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_TwoThousandEighteenPalnActivityMember" xlink:label="OCX_TwoThousandEighteenPalnActivityMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_TwoThousandEighteenPalnActivityMember" xlink:to="OCX_TwoThousandEighteenPalnActivityMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_TwoThousandEighteenPalnActivityMember_lbl" xml:lang="en-US"> 2018 Incentive Plan Activity [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_JulyTwoThousandEighteenOfferingMember" xlink:label="OCX_JulyTwoThousandEighteenOfferingMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_JulyTwoThousandEighteenOfferingMember" xlink:to="OCX_JulyTwoThousandEighteenOfferingMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_JulyTwoThousandEighteenOfferingMember_lbl" xml:lang="en-US"> July 2018 Offering [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_CommonStockAndWarrantsMember" xlink:label="OCX_CommonStockAndWarrantsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_CommonStockAndWarrantsMember" xlink:to="OCX_CommonStockAndWarrantsMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_CommonStockAndWarrantsMember_lbl" xml:lang="en-US"> Common Stock and Warrants [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember_lbl" xml:lang="en-US"> Accumulated Other Comprehensive Loss [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="us-gaap_RetainedEarningsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsMember" xlink:to="us-gaap_RetainedEarningsMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetainedEarningsMember_lbl" xml:lang="en-US"> Accumulated Deficit [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xml:lang="en-US"> Property, Plant and Equipment, Type [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_LaboratoryEquipmentMember" xlink:label="OCX_LaboratoryEquipmentMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LaboratoryEquipmentMember" xlink:to="OCX_LaboratoryEquipmentMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_LaboratoryEquipmentMember_lbl" xml:lang="en-US"> Laboratory Equipment [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MaximumMember" xlink:to="srt_MaximumMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_MaximumMember_lbl" xml:lang="en-US"> Maximum [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_AgeXTherapeuticsIncMember" xlink:label="OCX_AgeXTherapeuticsIncMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AgeXTherapeuticsIncMember" xlink:to="OCX_AgeXTherapeuticsIncMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_AgeXTherapeuticsIncMember_lbl" xml:lang="en-US"> AgeX Therapeutics, Inc [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_SharedFacilitiesAgreementMember" xlink:label="OCX_SharedFacilitiesAgreementMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SharedFacilitiesAgreementMember" xlink:to="OCX_SharedFacilitiesAgreementMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_SharedFacilitiesAgreementMember_lbl" xml:lang="en-US"> Shared Facilities Agreement [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_EmployeesAndConsultantsMember" xlink:label="OCX_EmployeesAndConsultantsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EmployeesAndConsultantsMember" xlink:to="OCX_EmployeesAndConsultantsMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_EmployeesAndConsultantsMember_lbl" xml:lang="en-US"> Employees and Consultants [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_PerformanceBasedOptionsMember" xlink:label="OCX_PerformanceBasedOptionsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PerformanceBasedOptionsMember" xlink:to="OCX_PerformanceBasedOptionsMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_PerformanceBasedOptionsMember_lbl" xml:lang="en-US"> Performance-Based Options [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_EmployeesMember" xlink:label="OCX_EmployeesMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EmployeesMember" xlink:to="OCX_EmployeesMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_EmployeesMember_lbl" xml:lang="en-US"> Employees [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_LegalEntityAxis" xlink:label="dei_LegalEntityAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LegalEntityAxis" xlink:to="dei_LegalEntityAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_LegalEntityAxis_lbl" xml:lang="en-US"> Legal Entity [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_RazorGenomicsIncMember" xlink:label="OCX_RazorGenomicsIncMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RazorGenomicsIncMember" xlink:to="OCX_RazorGenomicsIncMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_RazorGenomicsIncMember_lbl" xml:lang="en-US"> Razor Genomics, Inc. [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_BroadwoodPartnersLPAndGeorgeKarfunkelMember" xlink:label="OCX_BroadwoodPartnersLPAndGeorgeKarfunkelMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_BroadwoodPartnersLPAndGeorgeKarfunkelMember" xlink:to="OCX_BroadwoodPartnersLPAndGeorgeKarfunkelMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_BroadwoodPartnersLPAndGeorgeKarfunkelMember_lbl" xml:lang="en-US"> Broadwood Partners, L.P. and George Karfunkel [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_StatementClassOfStockAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementClassOfStockAxis_lbl" xml:lang="en-US"> Class of Stock [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_SeriesAConvertiblePreferredStockMember" xlink:label="OCX_SeriesAConvertiblePreferredStockMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SeriesAConvertiblePreferredStockMember" xlink:to="OCX_SeriesAConvertiblePreferredStockMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_SeriesAConvertiblePreferredStockMember_lbl" xml:lang="en-US"> Series A Convertible Preferred Stock [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_PurchaseAgreementMember" xlink:label="OCX_PurchaseAgreementMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PurchaseAgreementMember" xlink:to="OCX_PurchaseAgreementMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_PurchaseAgreementMember_lbl" xml:lang="en-US"> Purchase Agreement [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_DevelopmentAgreementMember" xlink:label="OCX_DevelopmentAgreementMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DevelopmentAgreementMember" xlink:to="OCX_DevelopmentAgreementMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_DevelopmentAgreementMember_lbl" xml:lang="en-US"> Development Agreement [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_EncoreClinicalIncMember" xlink:label="OCX_EncoreClinicalIncMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EncoreClinicalIncMember" xlink:to="OCX_EncoreClinicalIncMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_EncoreClinicalIncMember_lbl" xml:lang="en-US"> Encore Clinical, Inc. [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_LaboratoryAgreementMember" xlink:label="OCX_LaboratoryAgreementMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LaboratoryAgreementMember" xlink:to="OCX_LaboratoryAgreementMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_LaboratoryAgreementMember_lbl" xml:lang="en-US"> Laboratory Agreement [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_RonaldAndrewsMember" xlink:label="OCX_RonaldAndrewsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RonaldAndrewsMember" xlink:to="OCX_RonaldAndrewsMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_RonaldAndrewsMember_lbl" xml:lang="en-US"> Ronald Andrews [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PreferredStockMember" xlink:label="us-gaap_PreferredStockMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockMember" xlink:to="us-gaap_PreferredStockMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockMember_lbl" xml:lang="en-US"> Preferred Stock [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="us-gaap_SubsequentEventTypeAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTypeAxis" xlink:to="us-gaap_SubsequentEventTypeAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventTypeAxis_lbl" xml:lang="en-US"> Subsequent Event Type [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="us-gaap_SubsequentEventMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventMember" xlink:to="us-gaap_SubsequentEventMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventMember_lbl" xml:lang="en-US"> Subsequent Event [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_StockPurchaseAgreementsMember" xlink:label="OCX_StockPurchaseAgreementsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_StockPurchaseAgreementsMember" xlink:to="OCX_StockPurchaseAgreementsMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_StockPurchaseAgreementsMember_lbl" xml:lang="en-US"> Stock Purchase Agreements [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_EquityDistributionAgreementMember" xlink:label="OCX_EquityDistributionAgreementMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EquityDistributionAgreementMember" xlink:to="OCX_EquityDistributionAgreementMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_EquityDistributionAgreementMember_lbl" xml:lang="en-US"> Equity Distribution Agreement [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_PiperSandlerAndCoMember" xlink:label="OCX_PiperSandlerAndCoMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PiperSandlerAndCoMember" xlink:to="OCX_PiperSandlerAndCoMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_PiperSandlerAndCoMember_lbl" xml:lang="en-US"> Piper Sandler & Co [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MachineryAndEquipmentMember" xlink:label="us-gaap_MachineryAndEquipmentMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MachineryAndEquipmentMember" xlink:to="us-gaap_MachineryAndEquipmentMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MachineryAndEquipmentMember_lbl" xml:lang="en-US"> Machinery and Equipment [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquipmentMember" xlink:label="us-gaap_EquipmentMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquipmentMember" xlink:to="us-gaap_EquipmentMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquipmentMember_lbl" xml:lang="en-US"> Equipment [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_lbl" xml:lang="en-US"> Related Party [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_BroadwoodPartnersLPMember" xlink:label="OCX_BroadwoodPartnersLPMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_BroadwoodPartnersLPMember" xlink:to="OCX_BroadwoodPartnersLPMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_BroadwoodPartnersLPMember_lbl" xml:lang="en-US"> Broadwood Partners, L.P [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_AmendedLoanAgreementMember" xlink:label="OCX_AmendedLoanAgreementMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AmendedLoanAgreementMember" xlink:to="OCX_AmendedLoanAgreementMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_AmendedLoanAgreementMember_lbl" xml:lang="en-US"> Amended Loan Agreement [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_VestingAxis" xlink:label="us-gaap_VestingAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VestingAxis" xlink:to="us-gaap_VestingAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_VestingAxis_lbl" xml:lang="en-US"> Vesting [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheOneMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:to="us-gaap_ShareBasedCompensationAwardTrancheOneMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheOneMember_lbl" xml:lang="en-US"> Tranche One [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheTwoMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:to="us-gaap_ShareBasedCompensationAwardTrancheTwoMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationAwardTrancheTwoMember_lbl" xml:lang="en-US"> Tranche Two [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_BankWarrantMember" xlink:label="OCX_BankWarrantMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_BankWarrantMember" xlink:to="OCX_BankWarrantMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_BankWarrantMember_lbl" xml:lang="en-US"> Bank Warrant [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockAppreciationRightsSARSMember" xlink:label="us-gaap_StockAppreciationRightsSARSMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockAppreciationRightsSARSMember" xlink:to="us-gaap_StockAppreciationRightsSARSMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockAppreciationRightsSARSMember_lbl" xml:lang="en-US"> Stock Appreciation Rights (SARs) [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="us-gaap_RestrictedStockUnitsRSUMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockUnitsRSUMember" xlink:to="us-gaap_RestrictedStockUnitsRSUMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RestrictedStockUnitsRSUMember_lbl" xml:lang="en-US"> Restricted Stock Units (RSUs) [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_lbl" xml:lang="en-US"> Exercise Price Range [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ExercisePriceRangeOneMember" xlink:label="OCX_ExercisePriceRangeOneMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ExercisePriceRangeOneMember" xlink:to="OCX_ExercisePriceRangeOneMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ExercisePriceRangeOneMember_lbl" xml:lang="en-US"> Exercise Price Range One [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ExercisePriceRangeTwoMember" xlink:label="OCX_ExercisePriceRangeTwoMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ExercisePriceRangeTwoMember" xlink:to="OCX_ExercisePriceRangeTwoMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ExercisePriceRangeTwoMember_lbl" xml:lang="en-US"> Exercise Price Range Two [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ExercisePriceRangeThreeMember" xlink:label="OCX_ExercisePriceRangeThreeMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ExercisePriceRangeThreeMember" xlink:to="OCX_ExercisePriceRangeThreeMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ExercisePriceRangeThreeMember_lbl" xml:lang="en-US"> Exercise Price Range Three [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis" xlink:label="us-gaap_IncomeTaxAuthorityAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxAuthorityAxis" xlink:to="us-gaap_IncomeTaxAuthorityAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxAuthorityAxis_lbl" xml:lang="en-US"> Income Tax Authority [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_FederalMember" xlink:label="OCX_FederalMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FederalMember" xlink:to="OCX_FederalMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_FederalMember_lbl" xml:lang="en-US"> Federal [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_StateMember" xlink:label="OCX_StateMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_StateMember" xlink:to="OCX_StateMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_StateMember_lbl" xml:lang="en-US"> State [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_FederalandStateMember" xlink:label="OCX_FederalandStateMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FederalandStateMember" xlink:to="OCX_FederalandStateMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_FederalandStateMember_lbl" xml:lang="en-US"> Federal and State [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_OfficeLeaseAgreementMember" xlink:label="OCX_OfficeLeaseAgreementMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_OfficeLeaseAgreementMember" xlink:to="OCX_OfficeLeaseAgreementMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_OfficeLeaseAgreementMember_lbl" xml:lang="en-US"> Office Lease Agreement [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_StatementScenarioAxis" xlink:label="srt_StatementScenarioAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_StatementScenarioAxis" xlink:to="srt_StatementScenarioAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_StatementScenarioAxis_lbl" xml:lang="en-US"> Scenario [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_MonthlyRentMember" xlink:label="OCX_MonthlyRentMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_MonthlyRentMember" xlink:to="OCX_MonthlyRentMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_MonthlyRentMember_lbl" xml:lang="en-US"> Monthly Rent [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_FirstTenCalendarMember" xlink:label="OCX_FirstTenCalendarMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FirstTenCalendarMember" xlink:to="OCX_FirstTenCalendarMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_FirstTenCalendarMember_lbl" xml:lang="en-US"> First Ten Calendar [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_LandlordMember" xlink:label="OCX_LandlordMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LandlordMember" xlink:to="OCX_LandlordMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_LandlordMember_lbl" xml:lang="en-US"> Landlord [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_LicenseAgreementMember" xlink:label="OCX_LicenseAgreementMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LicenseAgreementMember" xlink:to="OCX_LicenseAgreementMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_LicenseAgreementMember_lbl" xml:lang="en-US"> License Agreement [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_SubscriptionAgreementsMember" xlink:label="OCX_SubscriptionAgreementsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SubscriptionAgreementsMember" xlink:to="OCX_SubscriptionAgreementsMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_SubscriptionAgreementsMember_lbl" xml:lang="en-US"> Subscription Agreements [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_MergerAgreementsMember" xlink:label="OCX_MergerAgreementsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_MergerAgreementsMember" xlink:to="OCX_MergerAgreementsMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_MergerAgreementsMember_lbl" xml:lang="en-US"> Merger Agreements [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_LeaseContractTypeAxis" xlink:label="OCX_LeaseContractTypeAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LeaseContractTypeAxis" xlink:to="OCX_LeaseContractTypeAxis_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_LeaseContractTypeAxis_lbl" xml:lang="en-US"> Lease Contract Type [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_OperatingLeaseMember" xlink:label="OCX_OperatingLeaseMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_OperatingLeaseMember" xlink:to="OCX_OperatingLeaseMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_OperatingLeaseMember_lbl" xml:lang="en-US"> Operating Lease [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_FinancingLeaseMember" xlink:label="OCX_FinancingLeaseMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FinancingLeaseMember" xlink:to="OCX_FinancingLeaseMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_FinancingLeaseMember_lbl" xml:lang="en-US"> Financing Lease [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_MinorityShareholdersMember" xlink:label="OCX_MinorityShareholdersMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_MinorityShareholdersMember" xlink:to="OCX_MinorityShareholdersMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_MinorityShareholdersMember_lbl" xml:lang="en-US"> Minority Shareholders [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ATMAgreementsMember" xlink:label="OCX_ATMAgreementsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ATMAgreementsMember" xlink:to="OCX_ATMAgreementsMember_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ATMAgreementsMember_lbl" xml:lang="en-US"> ATM Agreements [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_DocumentAndEntityInformationAbstract" xlink:label="OCX_DocumentAndEntityInformationAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DocumentAndEntityInformationAbstract" xlink:to="OCX_DocumentAndEntityInformationAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_DocumentAndEntityInformationAbstract_lbl" xml:lang="en-US"> Document And Entity Information </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityRegistrantName" xlink:to="dei_EntityRegistrantName_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityRegistrantName_lbl" xml:lang="en-US"> Entity Registrant Name </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCentralIndexKey" xlink:to="dei_EntityCentralIndexKey_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityCentralIndexKey_lbl" xml:lang="en-US"> Entity Central Index Key </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentType" xlink:label="dei_DocumentType"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentType" xlink:to="dei_DocumentType_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentType_lbl" xml:lang="en-US"> Document Type </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="dei_DocumentPeriodEndDate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentPeriodEndDate" xlink:to="dei_DocumentPeriodEndDate_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentPeriodEndDate_lbl" xml:lang="en-US"> Document Period End Date </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AmendmentFlag" xlink:to="dei_AmendmentFlag_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_AmendmentFlag_lbl" xml:lang="en-US"> Amendment Flag </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CurrentFiscalYearEndDate" xlink:to="dei_CurrentFiscalYearEndDate_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xml:lang="en-US"> Current Fiscal Year End Date </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityWellKnownSeasonedIssuer" xlink:label="dei_EntityWellKnownSeasonedIssuer"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityWellKnownSeasonedIssuer" xlink:to="dei_EntityWellKnownSeasonedIssuer_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityWellKnownSeasonedIssuer_lbl" xml:lang="en-US"> Entity Well Known Seasoned Issuer </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityVoluntaryFilers" xlink:label="dei_EntityVoluntaryFilers"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityVoluntaryFilers" xlink:to="dei_EntityVoluntaryFilers_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityVoluntaryFilers_lbl" xml:lang="en-US"> Entity Voluntary Filers </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityCurrentReportingStatus" xlink:label="dei_EntityCurrentReportingStatus"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCurrentReportingStatus" xlink:to="dei_EntityCurrentReportingStatus_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityCurrentReportingStatus_lbl" xml:lang="en-US"> Entity Current Reporting Status </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityInteractiveDataCurrent" xlink:label="dei_EntityInteractiveDataCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityInteractiveDataCurrent" xlink:to="dei_EntityInteractiveDataCurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityInteractiveDataCurrent_lbl" xml:lang="en-US"> Entity Interactive Data Current </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityFilerCategory" xlink:label="dei_EntityFilerCategory"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityFilerCategory" xlink:to="dei_EntityFilerCategory_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityFilerCategory_lbl" xml:lang="en-US"> Entity Filer Category </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntitySmallBusiness" xlink:label="dei_EntitySmallBusiness"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntitySmallBusiness" xlink:to="dei_EntitySmallBusiness_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntitySmallBusiness_lbl" xml:lang="en-US"> Entity Small Business Flag </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityEmergingGrowthCompany" xlink:label="dei_EntityEmergingGrowthCompany"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityEmergingGrowthCompany" xlink:to="dei_EntityEmergingGrowthCompany_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityEmergingGrowthCompany_lbl" xml:lang="en-US"> Entity Emerging Growth Company </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityExTransitionPeriod" xlink:label="dei_EntityExTransitionPeriod"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityExTransitionPeriod" xlink:to="dei_EntityExTransitionPeriod_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityExTransitionPeriod_lbl" xml:lang="en-US"> Entity Ex Transition Period </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityShellCompany" xlink:label="dei_EntityShellCompany"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityShellCompany" xlink:to="dei_EntityShellCompany_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityShellCompany_lbl" xml:lang="en-US"> Entity Shell Company </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityPublicFloat" xlink:label="dei_EntityPublicFloat"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityPublicFloat" xlink:to="dei_EntityPublicFloat_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityPublicFloat_lbl" xml:lang="en-US"> Entity Public Float </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCommonStockSharesOutstanding" xlink:to="dei_EntityCommonStockSharesOutstanding_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xml:lang="en-US"> Entity Common Stock, Shares Outstanding </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="dei_DocumentFiscalPeriodFocus"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFiscalPeriodFocus" xlink:to="dei_DocumentFiscalPeriodFocus_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentFiscalPeriodFocus_lbl" xml:lang="en-US"> Document Fiscal Period Focus </link:label>
<link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="dei_DocumentFiscalYearFocus"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFiscalYearFocus" xlink:to="dei_DocumentFiscalYearFocus_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentFiscalYearFocus_lbl" xml:lang="en-US"> Document Fiscal Year Focus </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="us-gaap_StatementOfFinancialPositionAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StatementOfFinancialPositionAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfFinancialPositionAbstract_lbl" xml:lang="en-US"> Statement of Financial Position [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="us-gaap_AssetsAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_AssetsAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsAbstract_lbl" xml:lang="en-US"> ASSETS </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="us-gaap_AssetsCurrentAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_AssetsCurrentAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xml:lang="en-US"> CURRENT ASSETS </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xml:lang="en-US"> Cash and cash equivalents </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquitySecuritiesFvNi" xlink:label="us-gaap_EquitySecuritiesFvNi"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquitySecuritiesFvNi" xlink:to="us-gaap_EquitySecuritiesFvNi_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquitySecuritiesFvNi_lbl" xml:lang="en-US"> Marketable equity securities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:to="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_lbl" xml:lang="en-US"> Prepaid expenses and other current assets </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AssetsCurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AssetsCurrent_lbl" xml:lang="en-US"> Total current assets </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsNoncurrentAbstract" xlink:label="us-gaap_AssetsNoncurrentAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsNoncurrentAbstract" xlink:to="us-gaap_AssetsNoncurrentAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsNoncurrentAbstract_lbl" xml:lang="en-US"> NONCURRENT ASSETS </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_RightofuseAssetsMachineryAndEquipmentNet" xlink:label="OCX_RightofuseAssetsMachineryAndEquipmentNet"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RightofuseAssetsMachineryAndEquipmentNet" xlink:to="OCX_RightofuseAssetsMachineryAndEquipmentNet_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_RightofuseAssetsMachineryAndEquipmentNet_lbl" xml:lang="en-US"> Right-of-use assets, machinery and equipment, net </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_DepositsAndOtherNoncurrentAssets" xlink:label="OCX_DepositsAndOtherNoncurrentAssets"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DepositsAndOtherNoncurrentAssets" xlink:to="OCX_DepositsAndOtherNoncurrentAssets_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_DepositsAndOtherNoncurrentAssets_lbl" xml:lang="en-US"> Deposits and other noncurrent assets </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvestments" xlink:label="us-gaap_EquityMethodInvestments"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestments" xlink:to="us-gaap_EquityMethodInvestments_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestments_lbl" xml:lang="en-US"> Equity method investment in Razor </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Assets_lbl" xml:lang="en-US"> TOTAL ASSETS </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xml:lang="en-US"> LIABILITIES AND SHAREHOLDERS' EQUITY </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="us-gaap_LiabilitiesCurrentAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_LiabilitiesCurrentAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xml:lang="en-US"> CURRENT LIABILITIES </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DueToRelatedPartiesCurrent" xlink:label="us-gaap_DueToRelatedPartiesCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DueToRelatedPartiesCurrent" xlink:to="us-gaap_DueToRelatedPartiesCurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DueToRelatedPartiesCurrent_lbl" xml:lang="en-US"> Amount due to Lineage and affiliates </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="us-gaap_AccountsPayableCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableCurrent" xlink:to="us-gaap_AccountsPayableCurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsPayableCurrent_lbl" xml:lang="en-US"> Accounts payable </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccountsPayableAndOtherAccruedLiabilitiesCurrent" xlink:label="us-gaap_AccountsPayableAndOtherAccruedLiabilitiesCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableAndOtherAccruedLiabilitiesCurrent" xlink:to="us-gaap_AccountsPayableAndOtherAccruedLiabilitiesCurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsPayableAndOtherAccruedLiabilitiesCurrent_lbl" xml:lang="en-US"> Accrued expenses and other current liabilities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LoansPayableCurrent" xlink:label="us-gaap_LoansPayableCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansPayableCurrent" xlink:to="us-gaap_LoansPayableCurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LoansPayableCurrent_lbl" xml:lang="en-US"> Loan payable, current </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_RightofuseAndFinancingLeaseLiabilitiesCurrent" xlink:label="OCX_RightofuseAndFinancingLeaseLiabilitiesCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RightofuseAndFinancingLeaseLiabilitiesCurrent" xlink:to="OCX_RightofuseAndFinancingLeaseLiabilitiesCurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_RightofuseAndFinancingLeaseLiabilitiesCurrent_lbl" xml:lang="en-US"> Right-of-use and financing lease liabilities, current </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_LiabilitiesCurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xml:lang="en-US"> Total current liabilities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesNoncurrentAbstract" xlink:label="us-gaap_LiabilitiesNoncurrentAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesNoncurrentAbstract" xlink:to="us-gaap_LiabilitiesNoncurrentAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesNoncurrentAbstract_lbl" xml:lang="en-US"> NONCURRENT LIABILITIES </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermLoansPayable" xlink:label="us-gaap_LongTermLoansPayable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermLoansPayable" xlink:to="us-gaap_LongTermLoansPayable_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermLoansPayable_lbl" xml:lang="en-US"> Loan payable, net of deferred financing costs, noncurrent </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_RightofuseAndFinancingLeaseLiabilitiesNoncurrent" xlink:label="OCX_RightofuseAndFinancingLeaseLiabilitiesNoncurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RightofuseAndFinancingLeaseLiabilitiesNoncurrent" xlink:to="OCX_RightofuseAndFinancingLeaseLiabilitiesNoncurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_RightofuseAndFinancingLeaseLiabilitiesNoncurrent_lbl" xml:lang="en-US"> Right-of-use and financing lease liabilities, noncurrent </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Liabilities_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Liabilities_lbl" xml:lang="en-US"> TOTAL LIABILITIES </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="us-gaap_CommitmentsAndContingencies"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingencies" xlink:to="us-gaap_CommitmentsAndContingencies_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingencies_lbl" xml:lang="en-US"> Commitments and contingencies (Note 10) </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="us-gaap_StockholdersEquityAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_StockholdersEquityAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xml:lang="en-US"> SHAREHOLDERS' EQUITY </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockValue" xlink:to="us-gaap_PreferredStockValue_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockValue_lbl" xml:lang="en-US"> Preferred stock, no par value, 5,000 shares authorized; none issued and outstanding </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValue" xlink:to="us-gaap_CommonStockValue_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockValue_lbl" xml:lang="en-US"> Common stock, no par value, 85,000 shares authorized; 57,032 and 40,664 shares issued and outstanding at December 31, 2019 and 2018, respectively </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xml:lang="en-US"> Accumulated other comprehensive loss </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xml:lang="en-US"> Accumulated deficit </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US"> Total shareholders' equity </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xml:lang="en-US"> TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PreferredStockNoParValue" xlink:label="us-gaap_PreferredStockNoParValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockNoParValue" xlink:to="us-gaap_PreferredStockNoParValue_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockNoParValue_lbl" xml:lang="en-US"> Preferred stock, no par value </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="us-gaap_PreferredStockSharesAuthorized"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesAuthorized" xlink:to="us-gaap_PreferredStockSharesAuthorized_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl" xml:lang="en-US"> Preferred stock, shares authorized </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="us-gaap_PreferredStockSharesIssued"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesIssued" xlink:to="us-gaap_PreferredStockSharesIssued_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockSharesIssued_lbl" xml:lang="en-US"> Preferred stock, shares issued </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="us-gaap_PreferredStockSharesOutstanding"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesOutstanding" xlink:to="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xml:lang="en-US"> Preferred stock, shares outstanding </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockNoParValue" xlink:label="us-gaap_CommonStockNoParValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockNoParValue" xlink:to="us-gaap_CommonStockNoParValue_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockNoParValue_lbl" xml:lang="en-US"> Common stock, no par value </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesAuthorized" xlink:to="us-gaap_CommonStockSharesAuthorized_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xml:lang="en-US"> Common stock, shares authorized </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesIssued" xlink:to="us-gaap_CommonStockSharesIssued_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xml:lang="en-US"> Common stock, shares issued </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesOutstanding" xlink:to="us-gaap_CommonStockSharesOutstanding_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xml:lang="en-US"> Common stock, shares outstanding </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeStatementAbstract" xlink:label="us-gaap_IncomeStatementAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeStatementAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeStatementAbstract_lbl" xml:lang="en-US"> Income Statement [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingExpensesAbstract" xlink:label="us-gaap_OperatingExpensesAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_OperatingExpensesAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingExpensesAbstract_lbl" xml:lang="en-US"> OPERATING EXPENSES </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="us-gaap_ResearchAndDevelopmentExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ResearchAndDevelopmentExpense" xlink:to="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xml:lang="en-US"> Research and development </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="us-gaap_GeneralAndAdministrativeExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GeneralAndAdministrativeExpense" xlink:to="us-gaap_GeneralAndAdministrativeExpense_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GeneralAndAdministrativeExpense_lbl" xml:lang="en-US"> General and administrative </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SellingAndMarketingExpense" xlink:label="us-gaap_SellingAndMarketingExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SellingAndMarketingExpense" xlink:to="us-gaap_SellingAndMarketingExpense_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SellingAndMarketingExpense_lbl" xml:lang="en-US"> Sales and marketing </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="us-gaap_OperatingExpenses"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpenses" xlink:to="us-gaap_OperatingExpenses_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingExpenses_lbl" xml:lang="en-US"> Total operating expenses </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingIncomeLoss_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xml:lang="en-US"> Loss from operations </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NonoperatingIncomeExpenseAbstract" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xml:lang="en-US"> OTHER INCOME (EXPENSES), NET </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:to="us-gaap_GainsLossesOnExtinguishmentOfDebt_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt_lbl" xml:lang="en-US"> Loss on extinguishment of debt </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_InterestIncomeExpenseNet" xlink:label="us-gaap_InterestIncomeExpenseNet"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestIncomeExpenseNet" xlink:to="us-gaap_InterestIncomeExpenseNet_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestIncomeExpenseNet_lbl" xml:lang="en-US"> Interest income (expense), net </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_MarketableSecuritiesUnrealizedGainLoss" xlink:label="us-gaap_MarketableSecuritiesUnrealizedGainLoss"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MarketableSecuritiesUnrealizedGainLoss" xlink:to="us-gaap_MarketableSecuritiesUnrealizedGainLoss_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MarketableSecuritiesUnrealizedGainLoss_lbl" xml:lang="en-US"> Unrealized loss on marketable equity securities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeLossFromEquityMethodInvestments" xlink:label="us-gaap_IncomeLossFromEquityMethodInvestments"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromEquityMethodInvestments" xlink:to="us-gaap_IncomeLossFromEquityMethodInvestments_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossFromEquityMethodInvestments_lbl" xml:lang="en-US"> Pro rata loss from equity method investment in Razor </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="us-gaap_OtherNonoperatingIncomeExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNonoperatingIncomeExpense" xlink:to="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xml:lang="en-US"> Other income (expense), net </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="us-gaap_NonoperatingIncomeExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="us-gaap_NonoperatingIncomeExpense_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xml:lang="en-US"> Total other expenses, net </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US"> NET LOSS </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted" xlink:label="us-gaap_EarningsPerShareBasicAndDiluted"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareBasicAndDiluted" xlink:to="us-gaap_EarningsPerShareBasicAndDiluted_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerShareBasicAndDiluted_lbl" xml:lang="en-US"> Net loss per share; basic and diluted </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:label="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:to="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_lbl" xml:lang="en-US"> Weighted average shares outstanding; basic and diluted </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:label="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_lbl" xml:lang="en-US"> Statement of Comprehensive Income [Abstract] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetIncomeLoss_2_lbl" xml:lang="en-US"> NET LOSS </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:to="us-gaap_OtherComprehensiveIncomeLossNetOfTax_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax_lbl" xml:lang="en-US"> Other comprehensive loss, net of tax </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComprehensiveIncomeNetOfTax" xlink:to="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xml:lang="en-US"> COMPREHENSIVE LOSS </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementTable_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementTable_lbl" xml:lang="en-US"> Statement [Table] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementLineItems_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementLineItems_lbl" xml:lang="en-US"> Statement [Line Items] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_StockholdersEquity_2_lbl" xml:lang="en-US"> Balance </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharesOutstanding" xlink:label="us-gaap_SharesOutstanding"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesOutstanding" xlink:to="us-gaap_SharesOutstanding_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_SharesOutstanding_lbl" xml:lang="en-US"> Balance, shares </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_NetIncomeLoss_3_lbl" xml:lang="en-US"> Net loss </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_CumulativeEffectOfAdjustmentForAdoptionOnAccumulatedOtherComprehensiveLoss" xlink:label="OCX_CumulativeEffectOfAdjustmentForAdoptionOnAccumulatedOtherComprehensiveLoss"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_CumulativeEffectOfAdjustmentForAdoptionOnAccumulatedOtherComprehensiveLoss" xlink:to="OCX_CumulativeEffectOfAdjustmentForAdoptionOnAccumulatedOtherComprehensiveLoss_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_CumulativeEffectOfAdjustmentForAdoptionOnAccumulatedOtherComprehensiveLoss_lbl" xml:lang="en-US"> Cumulative-effect adjustment for adoption of ASU 2016-01 on January 1, 2018 </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationGross" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationGross"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationGross" xlink:to="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationGross_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationGross_lbl" xml:lang="en-US"> Stock-based compensation </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationGross" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationGross"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationGross" xlink:to="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationGross_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationGross_lbl" xml:lang="en-US"> Stock-based compensation, shares </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl" xml:lang="en-US"> Sale of common shares and warrants </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xml:lang="en-US"> Sale of common shares and warrants, shares </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueOther" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueOther" xlink:to="us-gaap_StockIssuedDuringPeriodValueOther_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther_lbl" xml:lang="en-US"> Financing costs paid to issue common shares and warrants </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesOther" xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesOther" xlink:to="us-gaap_StockIssuedDuringPeriodSharesOther_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther_lbl" xml:lang="en-US"> Financing costs paid to issue common shares and warrants, shares </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:to="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_lbl" xml:lang="en-US"> Exercise of stock options </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xml:lang="en-US"> Exercise of stock options, shares </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockAndWarrantsIssuedDuringPeriodValuePreferredStockAndWarrants" xlink:label="us-gaap_StockAndWarrantsIssuedDuringPeriodValuePreferredStockAndWarrants"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockAndWarrantsIssuedDuringPeriodValuePreferredStockAndWarrants" xlink:to="us-gaap_StockAndWarrantsIssuedDuringPeriodValuePreferredStockAndWarrants_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockAndWarrantsIssuedDuringPeriodValuePreferredStockAndWarrants_lbl" xml:lang="en-US"> Issuance of warrants </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_StockIssuedDuringPeriodSharesIssuanceOfWarrants" xlink:label="OCX_StockIssuedDuringPeriodSharesIssuanceOfWarrants"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_StockIssuedDuringPeriodSharesIssuanceOfWarrants" xlink:to="OCX_StockIssuedDuringPeriodSharesIssuanceOfWarrants_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_StockIssuedDuringPeriodSharesIssuanceOfWarrants_lbl" xml:lang="en-US"> Issuance of warrants, shares </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_StockholdersEquity_3_lbl" xml:lang="en-US"> Balance </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesOutstanding" xlink:to="us-gaap_SharesOutstanding_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_SharesOutstanding_2_lbl" xml:lang="en-US"> Balance, shares </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:label="us-gaap_StatementOfCashFlowsAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_StatementOfCashFlowsAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xml:lang="en-US"> Statement of Cash Flows [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US"> CASH FLOWS FROM OPERATING ACTIVITIES: </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US"> Adjustments to reconcile net loss to net cash used in operating activities: </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_Depreciation" xlink:label="us-gaap_Depreciation"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Depreciation" xlink:to="us-gaap_Depreciation_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Depreciation_lbl" xml:lang="en-US"> Depreciation expense </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="us-gaap_AmortizationOfIntangibleAssets"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfIntangibleAssets" xlink:to="us-gaap_AmortizationOfIntangibleAssets_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AmortizationOfIntangibleAssets_lbl" xml:lang="en-US"> Amortization of intangible assets </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_AmortizationOfRightOfUseAssetsAndLiabilities" xlink:label="OCX_AmortizationOfRightOfUseAssetsAndLiabilities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AmortizationOfRightOfUseAssetsAndLiabilities" xlink:to="OCX_AmortizationOfRightOfUseAssetsAndLiabilities_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_AmortizationOfRightOfUseAssetsAndLiabilities_lbl" xml:lang="en-US"> Amortization of right of use assets and liabilities </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromEquityMethodInvestments" xlink:to="us-gaap_IncomeLossFromEquityMethodInvestments_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncomeLossFromEquityMethodInvestments_2_lbl" xml:lang="en-US"> Pro rata loss from equity method investment in Razor </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_AmortizationOfPrepaidMaintenance" xlink:label="OCX_AmortizationOfPrepaidMaintenance"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AmortizationOfPrepaidMaintenance" xlink:to="OCX_AmortizationOfPrepaidMaintenance_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_AmortizationOfPrepaidMaintenance_lbl" xml:lang="en-US"> Amortization of prepaid maintenance </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetImpairmentCharges" xlink:label="us-gaap_AssetImpairmentCharges"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetImpairmentCharges" xlink:to="us-gaap_AssetImpairmentCharges_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetImpairmentCharges_lbl" xml:lang="en-US"> Impairment charge for intangible assets </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensation" xlink:to="us-gaap_ShareBasedCompensation_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensation_lbl" xml:lang="en-US"> Stock-based compensation </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DividendIncomeOperating" xlink:label="us-gaap_DividendIncomeOperating"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendIncomeOperating" xlink:to="us-gaap_DividendIncomeOperating_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DividendIncomeOperating_lbl" xml:lang="en-US"> Dividend income from AgeX Therapeutics common stock received as a dividend-in-kind </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MarketableSecuritiesUnrealizedGainLoss" xlink:to="us-gaap_MarketableSecuritiesUnrealizedGainLoss_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_MarketableSecuritiesUnrealizedGainLoss_2_lbl" xml:lang="en-US"> Unrealized loss on marketable equity securities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AmortizationOfFinancingCosts" xlink:label="us-gaap_AmortizationOfFinancingCosts"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfFinancingCosts" xlink:to="us-gaap_AmortizationOfFinancingCosts_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AmortizationOfFinancingCosts_lbl" xml:lang="en-US"> Amortization of debt issuance costs </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:to="us-gaap_GainsLossesOnExtinguishmentOfDebt_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt_2_lbl" xml:lang="en-US"> Loss on extinguishment of debt </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IssuanceOfStockAndWarrantsForServicesOrClaims" xlink:label="us-gaap_IssuanceOfStockAndWarrantsForServicesOrClaims"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IssuanceOfStockAndWarrantsForServicesOrClaims" xlink:to="us-gaap_IssuanceOfStockAndWarrantsForServicesOrClaims_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IssuanceOfStockAndWarrantsForServicesOrClaims_lbl" xml:lang="en-US"> Warrants issued for advisory services </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherOperatingActivitiesCashFlowStatement" xlink:label="us-gaap_OtherOperatingActivitiesCashFlowStatement"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherOperatingActivitiesCashFlowStatement" xlink:to="us-gaap_OtherOperatingActivitiesCashFlowStatement_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherOperatingActivitiesCashFlowStatement_lbl" xml:lang="en-US"> Other </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xml:lang="en-US"> Changes in operating assets and liabilities: </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncreaseDecreaseInDueToRelatedParties" xlink:label="us-gaap_IncreaseDecreaseInDueToRelatedParties"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInDueToRelatedParties" xlink:to="us-gaap_IncreaseDecreaseInDueToRelatedParties_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncreaseDecreaseInDueToRelatedParties_lbl" xml:lang="en-US"> Amount due to Lineage and affiliates </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:to="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_lbl" xml:lang="en-US"> Prepaid expenses and other current assets </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_lbl" xml:lang="en-US"> Accounts payable and accrued liabilities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xml:lang="en-US"> Net cash used in operating activities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xml:lang="en-US"> CASH FLOWS FROM INVESTING ACTIVITIES: </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsToAcquireEquityMethodInvestments" xlink:label="us-gaap_PaymentsToAcquireEquityMethodInvestments"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireEquityMethodInvestments" xlink:to="us-gaap_PaymentsToAcquireEquityMethodInvestments_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquireEquityMethodInvestments_lbl" xml:lang="en-US"> Equity method investment in Razor </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xml:lang="en-US"> Purchase of equipment </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_PaymentsToSecurityDepositAndOther" xlink:label="OCX_PaymentsToSecurityDepositAndOther"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PaymentsToSecurityDepositAndOther" xlink:to="OCX_PaymentsToSecurityDepositAndOther_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="OCX_PaymentsToSecurityDepositAndOther_lbl" xml:lang="en-US"> Security deposit and other </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xml:lang="en-US"> Net cash used in investing activities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xml:lang="en-US"> CASH FLOWS FROM FINANCING ACTIVITIES: </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="us-gaap_ProceedsFromStockOptionsExercised"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromStockOptionsExercised" xlink:to="us-gaap_ProceedsFromStockOptionsExercised_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromStockOptionsExercised_lbl" xml:lang="en-US"> Proceeds from exercise of stock options </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl" xml:lang="en-US"> Proceeds from sale of common shares </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsOfStockIssuanceCosts" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfStockIssuanceCosts" xlink:to="us-gaap_PaymentsOfStockIssuanceCosts_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts_lbl" xml:lang="en-US"> Financing costs to issue common shares </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ProceedsFromSaleOfCommonStockAndWarrants" xlink:label="OCX_ProceedsFromSaleOfCommonStockAndWarrants"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ProceedsFromSaleOfCommonStockAndWarrants" xlink:to="OCX_ProceedsFromSaleOfCommonStockAndWarrants_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ProceedsFromSaleOfCommonStockAndWarrants_lbl" xml:lang="en-US"> Proceeds from sale of common shares and warrants </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_FinancingCostsToIssueCommonSharesAndWarrants" xlink:label="OCX_FinancingCostsToIssueCommonSharesAndWarrants"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FinancingCostsToIssueCommonSharesAndWarrants" xlink:to="OCX_FinancingCostsToIssueCommonSharesAndWarrants_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="OCX_FinancingCostsToIssueCommonSharesAndWarrants_lbl" xml:lang="en-US"> Financing costs to issue common shares and warrants </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProceedsFromRepaymentsOfDebt" xlink:label="us-gaap_ProceedsFromRepaymentsOfDebt"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromRepaymentsOfDebt" xlink:to="us-gaap_ProceedsFromRepaymentsOfDebt_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromRepaymentsOfDebt_lbl" xml:lang="en-US"> Proceeds from refinance of bank loan </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_RepaymentsOfPrincipalAndBankFeesFromRefinancingOfBankLoan" xlink:label="OCX_RepaymentsOfPrincipalAndBankFeesFromRefinancingOfBankLoan"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RepaymentsOfPrincipalAndBankFeesFromRefinancingOfBankLoan" xlink:to="OCX_RepaymentsOfPrincipalAndBankFeesFromRefinancingOfBankLoan_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="OCX_RepaymentsOfPrincipalAndBankFeesFromRefinancingOfBankLoan_lbl" xml:lang="en-US"> Payoff of principal and bank fees from refinancing of bank loan </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RepaymentsOfDebt" xlink:label="us-gaap_RepaymentsOfDebt"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfDebt" xlink:to="us-gaap_RepaymentsOfDebt_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_RepaymentsOfDebt_lbl" xml:lang="en-US"> Repayment of principal of loan payable prior to refinancing </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeasePrincipalPayments" xlink:label="us-gaap_FinanceLeasePrincipalPayments"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeasePrincipalPayments" xlink:to="us-gaap_FinanceLeasePrincipalPayments_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_FinanceLeasePrincipalPayments_lbl" xml:lang="en-US"> Repayment of financing lease obligations </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xml:lang="en-US"> Net cash provided by financing activities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_lbl" xml:lang="en-US"> NET INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffectAbstract" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffectAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffectAbstract" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffectAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffectAbstract_lbl" xml:lang="en-US"> CASH, CASH EQUIVALENTS AND RESTRICTED CASH: </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_lbl" xml:lang="en-US"> At beginning of the year </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_2_lbl" xml:lang="en-US"> At end of the year </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="us-gaap_SupplementalCashFlowInformationAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract_lbl" xml:lang="en-US"> SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_InterestPaidNet" xlink:label="us-gaap_InterestPaidNet"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPaidNet" xlink:to="us-gaap_InterestPaidNet_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestPaidNet_lbl" xml:lang="en-US"> Cash paid for interest </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="us-gaap_NoncashInvestingAndFinancingItemsAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract_lbl" xml:lang="en-US"> SUPPLEMENTAL SCHEDULE OF NONCASH FINANCING AND INVESTING ACTIVITIES: </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_Seenote10foradditionaldisclosures" xlink:label="OCX_Seenote10foradditionaldisclosures"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_Seenote10foradditionaldisclosures" xlink:to="OCX_Seenote10foradditionaldisclosures_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_Seenote10foradditionaldisclosures_lbl" xml:lang="en-US"> SeeNote10ForAdditionalDisclosures </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_DeferredFinalCommitmentFeeForBankLoan" xlink:label="OCX_DeferredFinalCommitmentFeeForBankLoan"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DeferredFinalCommitmentFeeForBankLoan" xlink:to="OCX_DeferredFinalCommitmentFeeForBankLoan_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_DeferredFinalCommitmentFeeForBankLoan_lbl" xml:lang="en-US"> Deferred final commitment fee for bank loan </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_EquipmentPurchasedUnderFinancingLeases" xlink:label="OCX_EquipmentPurchasedUnderFinancingLeases"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EquipmentPurchasedUnderFinancingLeases" xlink:to="OCX_EquipmentPurchasedUnderFinancingLeases_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_EquipmentPurchasedUnderFinancingLeases_lbl" xml:lang="en-US"> Equipment purchased under financing leases </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:to="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_lbl" xml:lang="en-US"> Organization, Consolidation and Presentation of Financial Statements [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:to="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_lbl" xml:lang="en-US"> Organization, Description of the Business and Liquidity </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_AccountingPoliciesAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountingPoliciesAbstract_lbl" xml:lang="en-US"> Accounting Policies [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SignificantAccountingPoliciesTextBlock" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SignificantAccountingPoliciesTextBlock" xlink:to="us-gaap_SignificantAccountingPoliciesTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock_lbl" xml:lang="en-US"> Summary of Significant Accounting Policies </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BalanceSheetRelatedDisclosuresAbstract" xlink:label="us-gaap_BalanceSheetRelatedDisclosuresAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BalanceSheetRelatedDisclosuresAbstract" xlink:to="us-gaap_BalanceSheetRelatedDisclosuresAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BalanceSheetRelatedDisclosuresAbstract_lbl" xml:lang="en-US"> Balance Sheet Related Disclosures [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SupplementalBalanceSheetDisclosuresTextBlock" xlink:label="us-gaap_SupplementalBalanceSheetDisclosuresTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplementalBalanceSheetDisclosuresTextBlock" xlink:to="us-gaap_SupplementalBalanceSheetDisclosuresTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SupplementalBalanceSheetDisclosuresTextBlock_lbl" xml:lang="en-US"> Selected Balance Sheet Components </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionsAbstract" xlink:label="us-gaap_RelatedPartyTransactionsAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsAbstract" xlink:to="us-gaap_RelatedPartyTransactionsAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionsAbstract_lbl" xml:lang="en-US"> Related Party Transactions [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:label="us-gaap_RelatedPartyTransactionsDisclosureTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:to="us-gaap_RelatedPartyTransactionsDisclosureTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionsDisclosureTextBlock_lbl" xml:lang="en-US"> Related Party Transactions </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvestmentsAndJointVenturesAbstract" xlink:label="us-gaap_EquityMethodInvestmentsAndJointVenturesAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentsAndJointVenturesAbstract" xlink:to="us-gaap_EquityMethodInvestmentsAndJointVenturesAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentsAndJointVenturesAbstract_lbl" xml:lang="en-US"> Equity Method Investments and Joint Ventures [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvestmentsTextBlock" xlink:label="us-gaap_EquityMethodInvestmentsTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentsTextBlock" xlink:to="us-gaap_EquityMethodInvestmentsTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentsTextBlock_lbl" xml:lang="en-US"> Equity Method Investment in Razor Genomics, Inc. </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtDisclosureAbstract" xlink:label="us-gaap_DebtDisclosureAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtDisclosureAbstract" xlink:to="us-gaap_DebtDisclosureAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtDisclosureAbstract_lbl" xml:lang="en-US"> Debt Disclosure [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebtTextBlock" xlink:label="us-gaap_LongTermDebtTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtTextBlock" xlink:to="us-gaap_LongTermDebtTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtTextBlock_lbl" xml:lang="en-US"> Loan Payable to Silicon Valley Bank </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityAbstract" xlink:label="us-gaap_EquityAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityAbstract" xlink:to="us-gaap_EquityAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityAbstract_lbl" xml:lang="en-US"> Equity [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:to="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl" xml:lang="en-US"> Shareholders' Equity </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_lbl" xml:lang="en-US"> Share-based Payment Arrangement [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:to="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl" xml:lang="en-US"> Stock-Based Compensation </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="us-gaap_IncomeTaxDisclosureAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_IncomeTaxDisclosureAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxDisclosureAbstract_lbl" xml:lang="en-US"> Income Tax Disclosure [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxDisclosureTextBlock" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxDisclosureTextBlock" xlink:to="us-gaap_IncomeTaxDisclosureTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock_lbl" xml:lang="en-US"> Income Taxes </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl" xml:lang="en-US"> Commitments and Contingencies Disclosure [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xml:lang="en-US"> Commitments and Contingencies </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventsAbstract" xlink:label="us-gaap_SubsequentEventsAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventsAbstract" xlink:to="us-gaap_SubsequentEventsAbstract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventsAbstract_lbl" xml:lang="en-US"> Subsequent Events [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsequentEventsTextBlock" xlink:label="us-gaap_SubsequentEventsTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventsTextBlock" xlink:to="us-gaap_SubsequentEventsTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventsTextBlock_lbl" xml:lang="en-US"> Subsequent Events </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:label="us-gaap_BasisOfAccountingPolicyPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:to="us-gaap_BasisOfAccountingPolicyPolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BasisOfAccountingPolicyPolicyTextBlock_lbl" xml:lang="en-US"> Basis of Presentation </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_UseOfEstimates" xlink:label="us-gaap_UseOfEstimates"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UseOfEstimates" xlink:to="us-gaap_UseOfEstimates_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UseOfEstimates_lbl" xml:lang="en-US"> Use of Estimates </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_GoingConcernAssessmentPolicyTextBlock" xlink:label="OCX_GoingConcernAssessmentPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_GoingConcernAssessmentPolicyTextBlock" xlink:to="OCX_GoingConcernAssessmentPolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_GoingConcernAssessmentPolicyTextBlock_lbl" xml:lang="en-US"> Going Concern Assessment </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:label="us-gaap_FairValueMeasurementPolicyPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:to="us-gaap_FairValueMeasurementPolicyPolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueMeasurementPolicyPolicyTextBlock_lbl" xml:lang="en-US"> Fair Value Measurements </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:to="us-gaap_CashAndCashEquivalentsPolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock_lbl" xml:lang="en-US"> Cash and Cash Equivalents </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:label="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:to="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy_lbl" xml:lang="en-US"> Restricted Cash </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvestmentsPolicy" xlink:label="us-gaap_EquityMethodInvestmentsPolicy"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentsPolicy" xlink:to="us-gaap_EquityMethodInvestmentsPolicy_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentsPolicy_lbl" xml:lang="en-US"> Investments in Common Stock of Privately Held Companies </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_AccountingForSharesOfCommonStockPolicyTextBlock" xlink:label="OCX_AccountingForSharesOfCommonStockPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AccountingForSharesOfCommonStockPolicyTextBlock" xlink:to="OCX_AccountingForSharesOfCommonStockPolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_AccountingForSharesOfCommonStockPolicyTextBlock_lbl" xml:lang="en-US"> Accounting for Lineage and Agex Shares of Common Stock </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl" xml:lang="en-US"> Machinery and Equipment </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" xlink:label="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" xlink:to="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock_lbl" xml:lang="en-US"> Impairment of Long-lived Assets </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_AccountingForWarrantsPolicyTextBlock" xlink:label="OCX_AccountingForWarrantsPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AccountingForWarrantsPolicyTextBlock" xlink:to="OCX_AccountingForWarrantsPolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_AccountingForWarrantsPolicyTextBlock_lbl" xml:lang="en-US"> Accounting for Warrants </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxPolicyTextBlock" xlink:label="us-gaap_IncomeTaxPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxPolicyTextBlock" xlink:to="us-gaap_IncomeTaxPolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_lbl" xml:lang="en-US"> Income Taxes </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:to="us-gaap_ResearchAndDevelopmentExpensePolicy_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy_lbl" xml:lang="en-US"> Research and Development Expenses </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesPolicyTextBlock" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpensesPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SellingGeneralAndAdministrativeExpensesPolicyTextBlock" xlink:to="us-gaap_SellingGeneralAndAdministrativeExpensesPolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpensesPolicyTextBlock_lbl" xml:lang="en-US"> General and Administrative Expenses </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_SalesAndMarketingCostsPolicyTextBlock" xlink:label="OCX_SalesAndMarketingCostsPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SalesAndMarketingCostsPolicyTextBlock" xlink:to="OCX_SalesAndMarketingCostsPolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_SalesAndMarketingCostsPolicyTextBlock_lbl" xml:lang="en-US"> Sales and Marketing Expenses </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CompensationRelatedCostsPolicyTextBlock" xlink:label="us-gaap_CompensationRelatedCostsPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CompensationRelatedCostsPolicyTextBlock" xlink:to="us-gaap_CompensationRelatedCostsPolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CompensationRelatedCostsPolicyTextBlock_lbl" xml:lang="en-US"> Stock-based Compensation </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EarningsPerSharePolicyTextBlock" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerSharePolicyTextBlock" xlink:to="us-gaap_EarningsPerSharePolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock_lbl" xml:lang="en-US"> Net Loss Per Common Share </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:label="us-gaap_SegmentReportingPolicyPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:to="us-gaap_SegmentReportingPolicyPolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentReportingPolicyPolicyTextBlock_lbl" xml:lang="en-US"> Segments </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl" xml:lang="en-US"> Recently Adopted Accounting Pronouncements </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_RecentlyIssuedAccountingPronouncementsNotYetAdoptedPolicyTextBlock" xlink:label="OCX_RecentlyIssuedAccountingPronouncementsNotYetAdoptedPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RecentlyIssuedAccountingPronouncementsNotYetAdoptedPolicyTextBlock" xlink:to="OCX_RecentlyIssuedAccountingPronouncementsNotYetAdoptedPolicyTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_RecentlyIssuedAccountingPronouncementsNotYetAdoptedPolicyTextBlock_lbl" xml:lang="en-US"> Recently Issued Accounting Pronouncements Not Yet Adopted </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ScheduleOfReconciliationOfCashCashEquivalentsAndRestrictedCashTableTextBlock" xlink:label="OCX_ScheduleOfReconciliationOfCashCashEquivalentsAndRestrictedCashTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ScheduleOfReconciliationOfCashCashEquivalentsAndRestrictedCashTableTextBlock" xlink:to="OCX_ScheduleOfReconciliationOfCashCashEquivalentsAndRestrictedCashTableTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ScheduleOfReconciliationOfCashCashEquivalentsAndRestrictedCashTableTextBlock_lbl" xml:lang="en-US"> Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:to="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_lbl" xml:lang="en-US"> Common Stock Equivalents Excluded from Computation of Diluted Net Loss Per Share of Common Stock </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredCostsCapitalizedPrepaidAndOtherAssetsDisclosureTextBlock" xlink:label="us-gaap_DeferredCostsCapitalizedPrepaidAndOtherAssetsDisclosureTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredCostsCapitalizedPrepaidAndOtherAssetsDisclosureTextBlock" xlink:to="us-gaap_DeferredCostsCapitalizedPrepaidAndOtherAssetsDisclosureTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredCostsCapitalizedPrepaidAndOtherAssetsDisclosureTextBlock_lbl" xml:lang="en-US"> Schedule of Prepaid Expenses and Other Current Assets </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfOtherAssetsNoncurrentTextBlock" xlink:label="us-gaap_ScheduleOfOtherAssetsNoncurrentTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfOtherAssetsNoncurrentTextBlock" xlink:to="us-gaap_ScheduleOfOtherAssetsNoncurrentTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfOtherAssetsNoncurrentTextBlock_lbl" xml:lang="en-US"> Schedule of Deposits and Other Noncurrent Assets </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ScheduleOfAccruedExpensesAndOtherCurrentLiabilitiesTableTextBlock" xlink:label="OCX_ScheduleOfAccruedExpensesAndOtherCurrentLiabilitiesTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ScheduleOfAccruedExpensesAndOtherCurrentLiabilitiesTableTextBlock" xlink:to="OCX_ScheduleOfAccruedExpensesAndOtherCurrentLiabilitiesTableTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ScheduleOfAccruedExpensesAndOtherCurrentLiabilitiesTableTextBlock_lbl" xml:lang="en-US"> Schedule of Accrued Expenses and Other Current Liabilities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl" xml:lang="en-US"> Schedule of Right of Use Assets, Machinery and Equipment, Net </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ScheduleOfAggregateUseOfFeesChargedTableTextBlock" xlink:label="OCX_ScheduleOfAggregateUseOfFeesChargedTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ScheduleOfAggregateUseOfFeesChargedTableTextBlock" xlink:to="OCX_ScheduleOfAggregateUseOfFeesChargedTableTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ScheduleOfAggregateUseOfFeesChargedTableTextBlock_lbl" xml:lang="en-US"> Schedule of Aggregate Use of Fees Charged </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd#srt_ScheduleOfCondensedBalanceSheetTableTextBlock" xlink:label="srt_ScheduleOfCondensedBalanceSheetTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ScheduleOfCondensedBalanceSheetTableTextBlock" xlink:to="srt_ScheduleOfCondensedBalanceSheetTableTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ScheduleOfCondensedBalanceSheetTableTextBlock_lbl" xml:lang="en-US"> Schedule of Condensed Balance Sheet Information </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:label="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:to="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock_lbl" xml:lang="en-US"> Schedule of Future Cash Payments of Loan Payable </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" xml:lang="en-US"> Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:to="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl" xml:lang="en-US"> Summary of Stock Option Activity </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_SchduleOfStockOptionsOutstandingVestedAndExercisableTableTextBlock" xlink:label="OCX_SchduleOfStockOptionsOutstandingVestedAndExercisableTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SchduleOfStockOptionsOutstandingVestedAndExercisableTableTextBlock" xlink:to="OCX_SchduleOfStockOptionsOutstandingVestedAndExercisableTableTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_SchduleOfStockOptionsOutstandingVestedAndExercisableTableTextBlock_lbl" xml:lang="en-US"> Schdule of Stock Options Outstanding, Vested and Exercisable </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:to="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_lbl" xml:lang="en-US"> Summary of Stock-based Compensation Expense </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xlink:to="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock_lbl" xml:lang="en-US"> Schedule of Assumptions Used to Calculate Fair Value of Stock Options </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:to="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl" xml:lang="en-US"> Schedule of Components of Deferred Tax Assets and Liabilities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:to="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xml:lang="en-US"> Schedule of Income Tax Reconciliation </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock" xlink:label="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock" xlink:to="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock_lbl" xml:lang="en-US"> Schedule of Unrecognized Tax Benefit </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_OperatingAndFinanceLeaseCashFlowTableTextBlock" xlink:label="OCX_OperatingAndFinanceLeaseCashFlowTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_OperatingAndFinanceLeaseCashFlowTableTextBlock" xlink:to="OCX_OperatingAndFinanceLeaseCashFlowTableTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_OperatingAndFinanceLeaseCashFlowTableTextBlock_lbl" xml:lang="en-US"> Schedule of Supplemental Cash Flow Information Related to Operating and Financing Lease </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_OperatingAndFinanceLeaseBalanceSheetTableTextBlock" xlink:label="OCX_OperatingAndFinanceLeaseBalanceSheetTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_OperatingAndFinanceLeaseBalanceSheetTableTextBlock" xlink:to="OCX_OperatingAndFinanceLeaseBalanceSheetTableTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_OperatingAndFinanceLeaseBalanceSheetTableTextBlock_lbl" xml:lang="en-US"> Schedule of Supplemental Balance Sheet Information Related to Operating and Financing Leases </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ScheduleOfFutureMinimumLeaseCommitmentsForOperatingAndFinancingLeasesTableTextBlock" xlink:label="OCX_ScheduleOfFutureMinimumLeaseCommitmentsForOperatingAndFinancingLeasesTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ScheduleOfFutureMinimumLeaseCommitmentsForOperatingAndFinancingLeasesTableTextBlock" xlink:to="OCX_ScheduleOfFutureMinimumLeaseCommitmentsForOperatingAndFinancingLeasesTableTextBlock_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ScheduleOfFutureMinimumLeaseCommitmentsForOperatingAndFinancingLeasesTableTextBlock_lbl" xml:lang="en-US"> Schedule of Future Minimum Lease Commitments for Operating and Financing Leases </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsTable" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentsTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEquityMethodInvestmentsTable" xlink:to="us-gaap_ScheduleOfEquityMethodInvestmentsTable_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentsTable_lbl" xml:lang="en-US"> Schedule of Equity Method Investments [Table] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsLineItems" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentsLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEquityMethodInvestmentsLineItems" xlink:to="us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_lbl" xml:lang="en-US"> Schedule of Equity Method Investments [Line Items] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TypeOfArrangementAxis" xlink:to="us-gaap_TypeOfArrangementAxis_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_TypeOfArrangementAxis_2_lbl" xml:lang="en-US"> Collaborative Arrangement and Arrangement Other than Collaborative [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:to="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xml:lang="en-US"> Equity ownership percentage </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:to="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_lbl" xml:lang="en-US"> Number of shares sold </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:label="us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:to="us-gaap_SaleOfStockConsiderationReceivedOnTransaction_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SaleOfStockConsiderationReceivedOnTransaction_lbl" xml:lang="en-US"> Proceeds from offering </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable" xlink:label="us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable" xlink:to="us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_lbl" xml:lang="en-US"> Subsidiary or Equity Method Investee, Sale of Stock by Subsidiary or Equity Investee [Table] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SubsidiarySaleOfStockLineItems" xlink:label="us-gaap_SubsidiarySaleOfStockLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsidiarySaleOfStockLineItems" xlink:to="us-gaap_SubsidiarySaleOfStockLineItems_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsidiarySaleOfStockLineItems_lbl" xml:lang="en-US"> Subsidiary, Sale of Stock [Line Items] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RangeAxis" xlink:to="srt_RangeAxis_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="srt_RangeAxis_2_lbl" xml:lang="en-US"> Statistical Measurement [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_EquityMethodInvestmentDescription" xlink:label="OCX_EquityMethodInvestmentDescription"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EquityMethodInvestmentDescription" xlink:to="OCX_EquityMethodInvestmentDescription_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_EquityMethodInvestmentDescription_lbl" xml:lang="en-US"> Equity method investment, description </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_2_lbl" xml:lang="en-US"> Cash and cash equivalents balances </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_2_lbl" xml:lang="en-US"> Number of shares purchased </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DividendsCommonStockCash" xlink:label="us-gaap_DividendsCommonStockCash"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendsCommonStockCash" xlink:to="us-gaap_DividendsCommonStockCash_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DividendsCommonStockCash_lbl" xml:lang="en-US"> Common stock dividend </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_CommonStockSharesHeldAsAvailableForSaleSecurities" xlink:label="OCX_CommonStockSharesHeldAsAvailableForSaleSecurities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_CommonStockSharesHeldAsAvailableForSaleSecurities" xlink:to="OCX_CommonStockSharesHeldAsAvailableForSaleSecurities_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_CommonStockSharesHeldAsAvailableForSaleSecurities_lbl" xml:lang="en-US"> Shares held as available-for-sale securities, shares </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquitySecuritiesFvNi" xlink:to="us-gaap_EquitySecuritiesFvNi_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EquitySecuritiesFvNi_2_lbl" xml:lang="en-US"> Marketable equity securities, fair market value </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" xml:lang="en-US"> Estimated useful life of plant and equipment </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseTermOfContract" xlink:label="us-gaap_LesseeOperatingLeaseTermOfContract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseTermOfContract" xlink:to="us-gaap_LesseeOperatingLeaseTermOfContract_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseTermOfContract_lbl" xml:lang="en-US"> Lease term </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_IntangibleAssetsNoncashCharge" xlink:label="OCX_IntangibleAssetsNoncashCharge"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_IntangibleAssetsNoncashCharge" xlink:to="OCX_IntangibleAssetsNoncashCharge_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_IntangibleAssetsNoncashCharge_lbl" xml:lang="en-US"> Intangible assets noncash charge </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense" xlink:label="us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense" xlink:to="us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense_lbl" xml:lang="en-US"> Payment of interest and penalties </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xml:lang="en-US"> Income tax rate </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_NumberOfOperatingSegments" xlink:label="us-gaap_NumberOfOperatingSegments"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfOperatingSegments" xlink:to="us-gaap_NumberOfOperatingSegments_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NumberOfOperatingSegments_lbl" xml:lang="en-US"> Number of operating segment </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_LeaseTermDescription" xlink:label="OCX_LeaseTermDescription"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LeaseTermDescription" xlink:to="OCX_LeaseTermDescription_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_LeaseTermDescription_lbl" xml:lang="en-US"> Lease term description </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_RestrictedCashIncludedInDepositsAndOtherNoncurrentAssets" xlink:label="OCX_RestrictedCashIncludedInDepositsAndOtherNoncurrentAssets"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RestrictedCashIncludedInDepositsAndOtherNoncurrentAssets" xlink:to="OCX_RestrictedCashIncludedInDepositsAndOtherNoncurrentAssets_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_RestrictedCashIncludedInDepositsAndOtherNoncurrentAssets_lbl" xml:lang="en-US"> Restricted cash included in deposits and other noncurrent assets (see Note 10) </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_3_lbl" xml:lang="en-US"> Total cash, cash equivalents, and restricted cash as shown in the statements of cash flows </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:to="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_lbl" xml:lang="en-US"> Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_lbl" xml:lang="en-US"> Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xml:lang="en-US"> Antidilutive securities excluded from computation of earnings per share </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:to="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_lbl" xml:lang="en-US"> Schedule of Finite-Lived Intangible Assets [Table] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl" xml:lang="en-US"> Finite-Lived Intangible Assets [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_WriteOffInDepreciatedAssets" xlink:label="OCX_WriteOffInDepreciatedAssets"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_WriteOffInDepreciatedAssets" xlink:to="OCX_WriteOffInDepreciatedAssets_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_WriteOffInDepreciatedAssets_lbl" xml:lang="en-US"> Write off in depreciated machinery and equipment </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_FinancingLeaseObligation" xlink:label="OCX_FinancingLeaseObligation"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FinancingLeaseObligation" xlink:to="OCX_FinancingLeaseObligation_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_FinancingLeaseObligation_lbl" xml:lang="en-US"> Financing leases </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PrepaidInsurance" xlink:label="us-gaap_PrepaidInsurance"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidInsurance" xlink:to="us-gaap_PrepaidInsurance_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PrepaidInsurance_lbl" xml:lang="en-US"> Prepaid insurance </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_PrepaidVendorsDepositsAndServiceAgreements" xlink:label="OCX_PrepaidVendorsDepositsAndServiceAgreements"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PrepaidVendorsDepositsAndServiceAgreements" xlink:to="OCX_PrepaidVendorsDepositsAndServiceAgreements_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_PrepaidVendorsDepositsAndServiceAgreements_lbl" xml:lang="en-US"> Prepaid vendors, deposits and service agreements </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:label="us-gaap_OtherAssetsCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssetsCurrent" xlink:to="us-gaap_OtherAssetsCurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OtherAssetsCurrent_lbl" xml:lang="en-US"> Other </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:to="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_2_lbl" xml:lang="en-US"> Total prepaid expenses and other current assets </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_RestrictedCashAndSecurityDepositForLease" xlink:label="OCX_RestrictedCashAndSecurityDepositForLease"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RestrictedCashAndSecurityDepositForLease" xlink:to="OCX_RestrictedCashAndSecurityDepositForLease_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_RestrictedCashAndSecurityDepositForLease_lbl" xml:lang="en-US"> Restricted cash and security deposit for the Irvine Lease (Note 10) </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PrepaidExpenseNoncurrent" xlink:label="us-gaap_PrepaidExpenseNoncurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseNoncurrent" xlink:to="us-gaap_PrepaidExpenseNoncurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PrepaidExpenseNoncurrent_lbl" xml:lang="en-US"> Long-term prepaid maintenance contracts </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="us-gaap_OtherAssetsNoncurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssetsNoncurrent" xlink:to="us-gaap_OtherAssetsNoncurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xml:lang="en-US"> Other </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DepositsAndOtherNoncurrentAssets" xlink:to="OCX_DepositsAndOtherNoncurrentAssets_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="OCX_DepositsAndOtherNoncurrentAssets_2_lbl" xml:lang="en-US"> Total deposits and other noncurrent assets </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:to="us-gaap_EmployeeRelatedLiabilitiesCurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent_lbl" xml:lang="en-US"> Accrued compensation </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherAccountsPayableAndAccruedLiabilities" xlink:label="us-gaap_OtherAccountsPayableAndAccruedLiabilities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAccountsPayableAndAccruedLiabilities" xlink:to="us-gaap_OtherAccountsPayableAndAccruedLiabilities_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherAccountsPayableAndAccruedLiabilities_lbl" xml:lang="en-US"> Accrued vendors and other expenses </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableAndOtherAccruedLiabilitiesCurrent" xlink:to="us-gaap_AccountsPayableAndOtherAccruedLiabilitiesCurrent_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AccountsPayableAndOtherAccruedLiabilitiesCurrent_2_lbl" xml:lang="en-US"> Total accrued expenses and other current liabilities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="us-gaap_PropertyPlantAndEquipmentGross"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentGross" xlink:to="us-gaap_PropertyPlantAndEquipmentGross_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xml:lang="en-US"> Machinery and equipment </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseRightOfUseAsset" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xml:lang="en-US"> Right-of-use assets for operating leases </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:to="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xml:lang="en-US"> Accumulated depreciation and amortization </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentNet" xlink:to="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US"> Right-of-use assets, machinery and equipment, net </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_lbl" xml:lang="en-US"> Schedule of Related Party Transactions, by Related Party [Table] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="us-gaap_RelatedPartyTransactionLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionLineItems" xlink:to="us-gaap_RelatedPartyTransactionLineItems_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionLineItems_lbl" xml:lang="en-US"> Related Party Transaction [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_PercentageOfMarkupFeeAllocatedButNotCharged" xlink:label="OCX_PercentageOfMarkupFeeAllocatedButNotCharged"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PercentageOfMarkupFeeAllocatedButNotCharged" xlink:to="OCX_PercentageOfMarkupFeeAllocatedButNotCharged_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_PercentageOfMarkupFeeAllocatedButNotCharged_lbl" xml:lang="en-US"> Markup rate on allocated costs </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_TermOfPayment" xlink:label="OCX_TermOfPayment"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_TermOfPayment" xlink:to="OCX_TermOfPayment_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_TermOfPayment_lbl" xml:lang="en-US"> Term of payment </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_InterestOnUnpaidOverdueInvoice" xlink:label="OCX_InterestOnUnpaidOverdueInvoice"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_InterestOnUnpaidOverdueInvoice" xlink:to="OCX_InterestOnUnpaidOverdueInvoice_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_InterestOnUnpaidOverdueInvoice_lbl" xml:lang="en-US"> Interest rate charged on unpaid and overdue invoices </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_AllocatedServicesAndFacilityUseFeePayable" xlink:label="OCX_AllocatedServicesAndFacilityUseFeePayable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AllocatedServicesAndFacilityUseFeePayable" xlink:to="OCX_AllocatedServicesAndFacilityUseFeePayable_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_AllocatedServicesAndFacilityUseFeePayable_lbl" xml:lang="en-US"> Allocated use fees payable </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeasePayments" xlink:label="us-gaap_OperatingLeasePayments"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasePayments" xlink:to="us-gaap_OperatingLeasePayments_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasePayments_lbl" xml:lang="en-US"> Lease payment </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:to="us-gaap_ProceedsFromIssuanceOrSaleOfEquity_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity_lbl" xml:lang="en-US"> Proceeds from sale of equity </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:to="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_2_lbl" xml:lang="en-US"> Sale of equity </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesIssuedPricePerShare" xlink:to="us-gaap_SharesIssuedPricePerShare_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharesIssuedPricePerShare_lbl" xml:lang="en-US"> shares issued, price per share </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_NumberOfCommonStockSharesAvailableInEachSeparableUnit" xlink:label="OCX_NumberOfCommonStockSharesAvailableInEachSeparableUnit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_NumberOfCommonStockSharesAvailableInEachSeparableUnit" xlink:to="OCX_NumberOfCommonStockSharesAvailableInEachSeparableUnit_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_NumberOfCommonStockSharesAvailableInEachSeparableUnit_lbl" xml:lang="en-US"> Number of common shares available in each separable unit </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_NumberOfWarrantsAvailableInEachSeparableUnit" xlink:label="OCX_NumberOfWarrantsAvailableInEachSeparableUnit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_NumberOfWarrantsAvailableInEachSeparableUnit" xlink:to="OCX_NumberOfWarrantsAvailableInEachSeparableUnit_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_NumberOfWarrantsAvailableInEachSeparableUnit_lbl" xml:lang="en-US"> Number of warrants to purchase stock in each separable unit </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProceedsFromIssuanceOfPrivatePlacement" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfPrivatePlacement" xlink:to="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_lbl" xml:lang="en-US"> Proceeds from issuance of private placement </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LossContingencyDamagesAwardedValue" xlink:label="us-gaap_LossContingencyDamagesAwardedValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LossContingencyDamagesAwardedValue" xlink:to="us-gaap_LossContingencyDamagesAwardedValue_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LossContingencyDamagesAwardedValue_lbl" xml:lang="en-US"> Liquidated damages owed </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ProfessionalFees" xlink:label="us-gaap_ProfessionalFees"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProfessionalFees" xlink:to="us-gaap_ProfessionalFees_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProfessionalFees_lbl" xml:lang="en-US"> Consulting fees </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_UseFees" xlink:label="OCX_UseFees"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_UseFees" xlink:to="OCX_UseFees_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="OCX_UseFees_lbl" xml:lang="en-US"> Total Use Fees </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_NumberOfSharesPurchased" xlink:label="OCX_NumberOfSharesPurchased"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_NumberOfSharesPurchased" xlink:to="OCX_NumberOfSharesPurchased_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_NumberOfSharesPurchased_lbl" xml:lang="en-US"> Number of shares purchased </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockParOrStatedValuePerShare" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_lbl" xml:lang="en-US"> Preferred stock, par value </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvestmentAggregateCost" xlink:label="us-gaap_EquityMethodInvestmentAggregateCost"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentAggregateCost" xlink:to="us-gaap_EquityMethodInvestmentAggregateCost_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentAggregateCost_lbl" xml:lang="en-US"> Stock purchase price </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValue" xlink:to="us-gaap_CommonStockValue_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CommonStockValue_2_lbl" xml:lang="en-US"> Common stock value </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EquityMethodInvestmentDescriptionOfPrincipalActivities" xlink:label="us-gaap_EquityMethodInvestmentDescriptionOfPrincipalActivities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentDescriptionOfPrincipalActivities" xlink:to="us-gaap_EquityMethodInvestmentDescriptionOfPrincipalActivities_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EquityMethodInvestmentDescriptionOfPrincipalActivities_lbl" xml:lang="en-US"> Equity method investment, description </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ClinicalTrialExpenseReserveAmount" xlink:label="OCX_ClinicalTrialExpenseReserveAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ClinicalTrialExpenseReserveAmount" xlink:to="OCX_ClinicalTrialExpenseReserveAmount_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ClinicalTrialExpenseReserveAmount_lbl" xml:lang="en-US"> Clinical trial expense reserve amount </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_EstimatedClinicalTrialExpense" xlink:label="OCX_EstimatedClinicalTrialExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EstimatedClinicalTrialExpense" xlink:to="OCX_EstimatedClinicalTrialExpense_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_EstimatedClinicalTrialExpense_lbl" xml:lang="en-US"> Estimated clinical trial expense </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_MilestonePayment" xlink:label="OCX_MilestonePayment"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_MilestonePayment" xlink:to="OCX_MilestonePayment_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_MilestonePayment_lbl" xml:lang="en-US"> Milestone payment </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_MilestonePaymentDescription" xlink:label="OCX_MilestonePaymentDescription"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_MilestonePaymentDescription" xlink:to="OCX_MilestonePaymentDescription_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_MilestonePaymentDescription_lbl" xml:lang="en-US"> Milestone payment description </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodValueNewIssues_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_2_lbl" xml:lang="en-US"> Shares issued, value </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersCostsIncurredGross" xlink:label="us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersCostsIncurredGross"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersCostsIncurredGross" xlink:to="us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersCostsIncurredGross_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersCostsIncurredGross_lbl" xml:lang="en-US"> Additional funding amount </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_PaymentObligationAmount" xlink:label="OCX_PaymentObligationAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PaymentObligationAmount" xlink:to="OCX_PaymentObligationAmount_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_PaymentObligationAmount_lbl" xml:lang="en-US"> Payment obligation amount </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LeaseExpirationDate1" xlink:label="us-gaap_LeaseExpirationDate1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseExpirationDate1" xlink:to="us-gaap_LeaseExpirationDate1_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LeaseExpirationDate1_lbl" xml:lang="en-US"> Lease expiration period </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_PreliminaryCoverageMilestonePayment" xlink:label="OCX_PreliminaryCoverageMilestonePayment"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PreliminaryCoverageMilestonePayment" xlink:to="OCX_PreliminaryCoverageMilestonePayment_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_PreliminaryCoverageMilestonePayment_lbl" xml:lang="en-US"> Preliminary coverage milestone payment </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts" xlink:label="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts" xlink:to="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts_lbl" xml:lang="en-US"> Transaction expenses </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives" xlink:label="us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives" xlink:to="us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives_lbl" xml:lang="en-US"> Estimated useful life of Razor assay </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AssetsCurrent_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsCurrent_2_lbl" xml:lang="en-US"> Current assets </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AssetsNoncurrent" xlink:label="us-gaap_AssetsNoncurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsNoncurrent" xlink:to="us-gaap_AssetsNoncurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsNoncurrent_lbl" xml:lang="en-US"> Noncurrent assets </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Assets_2_lbl" xml:lang="en-US"> Total assets </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_LiabilitiesCurrent_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesCurrent_2_lbl" xml:lang="en-US"> Current liabilities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LiabilitiesNoncurrent" xlink:label="us-gaap_LiabilitiesNoncurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesNoncurrent" xlink:to="us-gaap_LiabilitiesNoncurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesNoncurrent_lbl" xml:lang="en-US"> Noncurrent liabilities </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_4_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquity_4_lbl" xml:lang="en-US"> Stockholders’ equity </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_2_lbl" xml:lang="en-US"> Total liabilities and shareholders' equity </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentTable_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentTable_lbl" xml:lang="en-US"> Schedule of Long-term Debt Instruments [Table] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentLineItems_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentLineItems_lbl" xml:lang="en-US"> Debt Instrument [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="us-gaap_DebtInstrumentFaceAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentFaceAmount" xlink:to="us-gaap_DebtInstrumentFaceAmount_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xml:lang="en-US"> Amount borrowed </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentFrequencyOfPeriodicPayment" xlink:label="us-gaap_DebtInstrumentFrequencyOfPeriodicPayment"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentFrequencyOfPeriodicPayment" xlink:to="us-gaap_DebtInstrumentFrequencyOfPeriodicPayment_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentFrequencyOfPeriodicPayment_lbl" xml:lang="en-US"> Periodic payment term </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentPeriodicPayment" xlink:label="us-gaap_DebtInstrumentPeriodicPayment"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentPeriodicPayment" xlink:to="us-gaap_DebtInstrumentPeriodicPayment_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentPeriodicPayment_lbl" xml:lang="en-US"> Periodic payments of principal and interest </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentMaturityDate" xlink:label="us-gaap_DebtInstrumentMaturityDate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentMaturityDate" xlink:to="us-gaap_DebtInstrumentMaturityDate_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl" xml:lang="en-US"> Debt instrument, maturity date </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfFinancingCosts" xlink:to="us-gaap_AmortizationOfFinancingCosts_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AmortizationOfFinancingCosts_2_lbl" xml:lang="en-US"> Amortization of deferred financing costs </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_PrepaymentFeeIfPrepaidTwoYearsOrMore" xlink:label="OCX_PrepaymentFeeIfPrepaidTwoYearsOrMore"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PrepaymentFeeIfPrepaidTwoYearsOrMore" xlink:to="OCX_PrepaymentFeeIfPrepaidTwoYearsOrMore_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_PrepaymentFeeIfPrepaidTwoYearsOrMore_lbl" xml:lang="en-US"> Prepayment fee if prepaid two years or more </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebtPercentageBearingFixedInterestRate" xlink:label="us-gaap_LongTermDebtPercentageBearingFixedInterestRate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtPercentageBearingFixedInterestRate" xlink:to="us-gaap_LongTermDebtPercentageBearingFixedInterestRate_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtPercentageBearingFixedInterestRate_lbl" xml:lang="en-US"> Interest rate on obligations due to bank </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_DebtDefaultLegalActionAmount" xlink:label="OCX_DebtDefaultLegalActionAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DebtDefaultLegalActionAmount" xlink:to="OCX_DebtDefaultLegalActionAmount_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_DebtDefaultLegalActionAmount_lbl" xml:lang="en-US"> Minimum legal judgments or legal actions amount triggering loan default </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:to="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_lbl" xml:lang="en-US"> Warrants to purchase, shares </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl" xml:lang="en-US"> Warrant exercise price, per share </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredFinanceCostsNet" xlink:label="us-gaap_DeferredFinanceCostsNet"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredFinanceCostsNet" xlink:to="us-gaap_DeferredFinanceCostsNet_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredFinanceCostsNet_lbl" xml:lang="en-US"> Deferred financing costs </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsOfDebtIssuanceCosts" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfDebtIssuanceCosts" xlink:to="us-gaap_PaymentsOfDebtIssuanceCosts_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts_lbl" xml:lang="en-US"> Aggregate deferred financing costs </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LinesOfCreditCurrent" xlink:label="us-gaap_LinesOfCreditCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LinesOfCreditCurrent" xlink:to="us-gaap_LinesOfCreditCurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LinesOfCreditCurrent_lbl" xml:lang="en-US"> Secured credit facility </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RepaymentsOfLinesOfCredit" xlink:label="us-gaap_RepaymentsOfLinesOfCredit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfLinesOfCredit" xlink:to="us-gaap_RepaymentsOfLinesOfCredit_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RepaymentsOfLinesOfCredit_lbl" xml:lang="en-US"> Repayment of remaining balance </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid" xlink:label="us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid" xlink:to="us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid_lbl" xml:lang="en-US"> Debt instrument, final payment </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapital" xlink:to="us-gaap_AdditionalPaidInCapital_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdditionalPaidInCapital_lbl" xml:lang="en-US"> Additional equity capital </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCreditFacilityDescription" xlink:label="us-gaap_LineOfCreditFacilityDescription"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityDescription" xlink:to="us-gaap_LineOfCreditFacilityDescription_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityDescription_lbl" xml:lang="en-US"> Line of credit, description </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:label="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:to="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_lbl" xml:lang="en-US"> Interest rate </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentInterestRateDuringPeriod" xlink:label="us-gaap_DebtInstrumentInterestRateDuringPeriod"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateDuringPeriod" xlink:to="us-gaap_DebtInstrumentInterestRateDuringPeriod_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentInterestRateDuringPeriod_lbl" xml:lang="en-US"> Prime rate plus variable spread per annum </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LineOfCreditFacilityInterestRateDescription" xlink:label="us-gaap_LineOfCreditFacilityInterestRateDescription"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityInterestRateDescription" xlink:to="us-gaap_LineOfCreditFacilityInterestRateDescription_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityInterestRateDescription_lbl" xml:lang="en-US"> Interest rate description </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_DilutedEquityOutstanding" xlink:label="OCX_DilutedEquityOutstanding"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DilutedEquityOutstanding" xlink:to="OCX_DilutedEquityOutstanding_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_DilutedEquityOutstanding_lbl" xml:lang="en-US"> Diluted equity outstanding </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl" xml:lang="en-US"> 2020 </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl" xml:lang="en-US"> 2021 </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl" xml:lang="en-US"> 2022 </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_PaymentsOfPrincipalAndInterest" xlink:label="OCX_PaymentsOfPrincipalAndInterest"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PaymentsOfPrincipalAndInterest" xlink:to="OCX_PaymentsOfPrincipalAndInterest_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="OCX_PaymentsOfPrincipalAndInterest_lbl" xml:lang="en-US"> Total payments of principal and interest </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_LoanPayableAmountsRepresentingInterest" xlink:label="OCX_LoanPayableAmountsRepresentingInterest"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LoanPayableAmountsRepresentingInterest" xlink:to="OCX_LoanPayableAmountsRepresentingInterest_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_LoanPayableAmountsRepresentingInterest_lbl" xml:lang="en-US"> Less: amounts representing interest </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="us-gaap_DebtInstrumentCarryingAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentCarryingAmount" xlink:to="us-gaap_DebtInstrumentCarryingAmount_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl" xml:lang="en-US"> Total payments of principal before deferred financing costs </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredFinanceCostsNet" xlink:to="us-gaap_DeferredFinanceCostsNet_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DeferredFinanceCostsNet_2_lbl" xml:lang="en-US"> Less: deferred financing costs </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LoansPayable" xlink:label="us-gaap_LoansPayable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansPayable" xlink:to="us-gaap_LoansPayable_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LoansPayable_lbl" xml:lang="en-US"> Total loan payable, net of deferred financing costs </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockNoParValue" xlink:to="us-gaap_PreferredStockNoParValue_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PreferredStockNoParValue_2_lbl" xml:lang="en-US"> Preferred stock par value </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockNoParValue" xlink:to="us-gaap_CommonStockNoParValue_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CommonStockNoParValue_2_lbl" xml:lang="en-US"> Common stock par value </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_CommonStockPurchaseWarrantsSharesIssued" xlink:label="OCX_CommonStockPurchaseWarrantsSharesIssued"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_CommonStockPurchaseWarrantsSharesIssued" xlink:to="OCX_CommonStockPurchaseWarrantsSharesIssued_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_CommonStockPurchaseWarrantsSharesIssued_lbl" xml:lang="en-US"> Common stock purchase warrants, shares issued </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ClassOfWarrantOrRightOutstanding" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightOutstanding" xlink:to="us-gaap_ClassOfWarrantOrRightOutstanding_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding_lbl" xml:lang="en-US"> Common stock purchase warrants, shares outstanding </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_2_lbl" xml:lang="en-US"> Common stock purchase warrants, exercise price </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_WarrantsAndRightsOutstandingMaturityDate" xlink:label="us-gaap_WarrantsAndRightsOutstandingMaturityDate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WarrantsAndRightsOutstandingMaturityDate" xlink:to="us-gaap_WarrantsAndRightsOutstandingMaturityDate_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WarrantsAndRightsOutstandingMaturityDate_lbl" xml:lang="en-US"> Warrant expiry date </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_lbl" xml:lang="en-US"> Common stock, shares authorized </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:to="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xml:lang="en-US"> Number of common stock reserved for future issuance </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xml:lang="en-US"> Number of option granted during the period </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_lbl" xml:lang="en-US"> Stock option weighted-average period </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDescription" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDescription"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDescription" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDescription_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDescription_lbl" xml:lang="en-US"> Stock options description </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_FairMarketValueOfCommonStockPercentage" xlink:label="OCX_FairMarketValueOfCommonStockPercentage"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FairMarketValueOfCommonStockPercentage" xlink:to="OCX_FairMarketValueOfCommonStockPercentage_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_FairMarketValueOfCommonStockPercentage_lbl" xml:lang="en-US"> Fair market value of common stock percentage </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_StockOptionExercisable" xlink:label="OCX_StockOptionExercisable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_StockOptionExercisable" xlink:to="OCX_StockOptionExercisable_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_StockOptionExercisable_lbl" xml:lang="en-US"> Stock options exercisable </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_lbl" xml:lang="en-US"> Exercise prices ranging, lower limit </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_lbl" xml:lang="en-US"> Exercise prices ranging, upper limit </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_lbl" xml:lang="en-US"> Option vested </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllocatedShareBasedCompensationExpense" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xml:lang="en-US"> Share based compensation expenses </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xml:lang="en-US"> Performance-based options outstanding </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_lbl" xml:lang="en-US"> Unrecognized compensation expense </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_lbl" xml:lang="en-US"> Unrecognized compensation expense recognized over a weighted-average period </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Fair value option exercise price per share </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_lbl" xml:lang="en-US"> Shares available for grant options, beginning of period </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_SharesAvailableForGrantOutstanding" xlink:label="OCX_SharesAvailableForGrantOutstanding"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SharesAvailableForGrantOutstanding" xlink:to="OCX_SharesAvailableForGrantOutstanding_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_SharesAvailableForGrantOutstanding_lbl" xml:lang="en-US"> Shares available for grant outstanding, approval of 2018 incentive plan </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedOptionPoolIncrease" xlink:label="OCX_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedOptionPoolIncrease"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedOptionPoolIncrease" xlink:to="OCX_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedOptionPoolIncrease_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedOptionPoolIncrease_lbl" xml:lang="en-US"> Shares available for grant option pool increase </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableGrantsInPeriodGross" xlink:label="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableGrantsInPeriodGross"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableGrantsInPeriodGross" xlink:to="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableGrantsInPeriodGross_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableGrantsInPeriodGross_lbl" xml:lang="en-US"> Shares available for grant options granted </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableRestrictedStockOptionsGrantsInPeriodGross" xlink:label="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableRestrictedStockOptionsGrantsInPeriodGross"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableRestrictedStockOptionsGrantsInPeriodGross" xlink:to="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableRestrictedStockOptionsGrantsInPeriodGross_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableRestrictedStockOptionsGrantsInPeriodGross_lbl" xml:lang="en-US"> Shares available for grant options RSUs granted </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_2_lbl" xml:lang="en-US"> Shares available for grant options exercised </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares_lbl" xml:lang="en-US"> Shares available for grant options forfeited canceled and expired </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_SharesAvailableForGrantOptionsTermination" xlink:label="OCX_SharesAvailableForGrantOptionsTermination"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SharesAvailableForGrantOptionsTermination" xlink:to="OCX_SharesAvailableForGrantOptionsTermination_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_SharesAvailableForGrantOptionsTermination_lbl" xml:lang="en-US"> Shares available for grant options, termination of the 2010 plan </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_2_lbl" xml:lang="en-US"> Shares available for grant outstanding, end of period </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_2_lbl" xml:lang="en-US"> Number of options outstanding, beginning of period </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_NumberOfOptionsOutstandingApprovalOfTwoThousandEighteenIncentivePlan" xlink:label="OCX_NumberOfOptionsOutstandingApprovalOfTwoThousandEighteenIncentivePlan"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_NumberOfOptionsOutstandingApprovalOfTwoThousandEighteenIncentivePlan" xlink:to="OCX_NumberOfOptionsOutstandingApprovalOfTwoThousandEighteenIncentivePlan_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_NumberOfOptionsOutstandingApprovalOfTwoThousandEighteenIncentivePlan_lbl" xml:lang="en-US"> Number of options outstanding, approval of 2018 incentive plan </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionPoolIncrease" xlink:label="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionPoolIncrease"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionPoolIncrease" xlink:to="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionPoolIncrease_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionPoolIncrease_lbl" xml:lang="en-US"> Number of options outstanding, option pool increase </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_2_lbl" xml:lang="en-US"> Number of options outstanding, option granted </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodGross" xlink:label="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodGross"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodGross" xlink:to="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodGross_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodGross_lbl" xml:lang="en-US"> Number of options outstanding, option rsus granted </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_2_lbl" xml:lang="en-US"> Number of options outstanding, options exercised </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_lbl" xml:lang="en-US"> Number of options outstanding, options forfeited and canceled </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_NumberOfOptionsOutstandingTermination" xlink:label="OCX_NumberOfOptionsOutstandingTermination"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_NumberOfOptionsOutstandingTermination" xlink:to="OCX_NumberOfOptionsOutstandingTermination_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_NumberOfOptionsOutstandingTermination_lbl" xml:lang="en-US"> Number of options outstanding, termination of the 2010 plan </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_3_lbl" xml:lang="en-US"> Number of options outstanding, end of period </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions_lbl" xml:lang="en-US"> Number of options outstanding, exercisable, end of period </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Weighted average exercise price, options outstanding, beginning of period </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_WeightedAverageExercisePriceApprovalOfTwoThousandEighteenIncentivePlan" xlink:label="OCX_WeightedAverageExercisePriceApprovalOfTwoThousandEighteenIncentivePlan"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_WeightedAverageExercisePriceApprovalOfTwoThousandEighteenIncentivePlan" xlink:to="OCX_WeightedAverageExercisePriceApprovalOfTwoThousandEighteenIncentivePlan_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_WeightedAverageExercisePriceApprovalOfTwoThousandEighteenIncentivePlan_lbl" xml:lang="en-US"> Weighted average exercise price, approval of 2018 incentive plan </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsPoolIncreaseInPeriodWeightedAverageExercisePrice" xlink:label="OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsPoolIncreaseInPeriodWeightedAverageExercisePrice"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsPoolIncreaseInPeriodWeightedAverageExercisePrice" xlink:to="OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsPoolIncreaseInPeriodWeightedAverageExercisePrice_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsPoolIncreaseInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Weighted average exercise price, option pool increase </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_2_lbl" xml:lang="en-US"> Weighted average exercise price, option granted </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodWeightedAverageExercisePrice"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:to="OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodWeightedAverageExercisePrice_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Weighted average exercise price, option rsus granted </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Weighted average exercise price, options exercised </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US"> Weighted average exercise price, options forfeited, canceled and expired </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_WeightedAverageExercisePriceOptionsTermination" xlink:label="OCX_WeightedAverageExercisePriceOptionsTermination"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_WeightedAverageExercisePriceOptionsTermination" xlink:to="OCX_WeightedAverageExercisePriceOptionsTermination_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_WeightedAverageExercisePriceOptionsTermination_lbl" xml:lang="en-US"> Weighted average exercise price, options termination of the 2010 plan </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_2_lbl" xml:lang="en-US"> Weighted average exercise price, outstanding end of period </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1" xlink:label="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1" xlink:to="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_lbl" xml:lang="en-US"> Weighted average exercise price, exercisable, end of period </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_2_lbl" xml:lang="en-US"> Options Outstanding, Weighted-Average Exercise Price, Minimum </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:to="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_2_lbl" xml:lang="en-US"> Options Outstanding, Weighted-Average Exercise Price, Maximum </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_4_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_4_lbl" xml:lang="en-US"> Options Outstanding, Number of Shares </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_2_lbl" xml:lang="en-US"> Options Outstanding, Weighted-Average Remaining Contractual Life (Years) </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_3_lbl" xml:lang="en-US"> Options Outstanding, Weighted-Average Exercise Price, </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensation" xlink:to="us-gaap_ShareBasedCompensation_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensation_2_lbl" xml:lang="en-US"> Total stock-based compensation expense </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl" xml:lang="en-US"> Expected life (in years) </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl" xml:lang="en-US"> Risk-free interest rates </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl" xml:lang="en-US"> Volatility </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_lbl" xml:lang="en-US"> Dividend yield </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xml:lang="en-US"> Provision for income taxes </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:to="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_lbl" xml:lang="en-US"> Net operating loss carryforwards </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_NetOperatingLossExpirationPeriodDescription" xlink:label="OCX_NetOperatingLossExpirationPeriodDescription"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_NetOperatingLossExpirationPeriodDescription" xlink:to="OCX_NetOperatingLossExpirationPeriodDescription_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_NetOperatingLossExpirationPeriodDescription_lbl" xml:lang="en-US"> Net operating loss expiration period description </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch" xlink:label="us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch" xlink:to="us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch_lbl" xml:lang="en-US"> Research and development credit carryforwards </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_CreditCarryforwardExpirationTerm" xlink:label="OCX_CreditCarryforwardExpirationTerm"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_CreditCarryforwardExpirationTerm" xlink:to="OCX_CreditCarryforwardExpirationTerm_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_CreditCarryforwardExpirationTerm_lbl" xml:lang="en-US"> Credit carryforward expiration term </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:to="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl" xml:lang="en-US"> Change in valuation allowance </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherInformationPertainingToIncomeTaxes" xlink:label="us-gaap_OtherInformationPertainingToIncomeTaxes"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherInformationPertainingToIncomeTaxes" xlink:to="us-gaap_OtherInformationPertainingToIncomeTaxes_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherInformationPertainingToIncomeTaxes_lbl" xml:lang="en-US"> Income tax other description </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="us-gaap_UnrecognizedTaxBenefits"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefits" xlink:to="us-gaap_UnrecognizedTaxBenefits_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xml:lang="en-US"> Uncertain tax benefits </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_IncomeTaxExaminationPenaltiesAndInterestAccrued" xlink:label="us-gaap_IncomeTaxExaminationPenaltiesAndInterestAccrued"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExaminationPenaltiesAndInterestAccrued" xlink:to="us-gaap_IncomeTaxExaminationPenaltiesAndInterestAccrued_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxExaminationPenaltiesAndInterestAccrued_lbl" xml:lang="en-US"> Accrued interest and penalties </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:to="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_2_lbl" xml:lang="en-US"> Net operating loss carryforwards and capital loss carryforwards </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredTaxAssetsEquityMethodInvestments" xlink:label="us-gaap_DeferredTaxAssetsEquityMethodInvestments"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsEquityMethodInvestments" xlink:to="us-gaap_DeferredTaxAssetsEquityMethodInvestments_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DeferredTaxAssetsEquityMethodInvestments_lbl" xml:lang="en-US"> Marketable equity securities </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_DeferredTaxAssetsPatentsAndFixedAssets" xlink:label="OCX_DeferredTaxAssetsPatentsAndFixedAssets"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DeferredTaxAssetsPatentsAndFixedAssets" xlink:to="OCX_DeferredTaxAssetsPatentsAndFixedAssets_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_DeferredTaxAssetsPatentsAndFixedAssets_lbl" xml:lang="en-US"> Patents and fixed assets </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost" xlink:to="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_lbl" xml:lang="en-US"> Stock-based and other compensation </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_DeferredTaxAssetsEquityMethodInvestment" xlink:label="OCX_DeferredTaxAssetsEquityMethodInvestment"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DeferredTaxAssetsEquityMethodInvestment" xlink:to="OCX_DeferredTaxAssetsEquityMethodInvestment_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="OCX_DeferredTaxAssetsEquityMethodInvestment_lbl" xml:lang="en-US"> Equity method investment in Razor </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_DeferredTaxRightOfUseLiability" xlink:label="OCX_DeferredTaxRightOfUseLiability"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DeferredTaxRightOfUseLiability" xlink:to="OCX_DeferredTaxRightOfUseLiability_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_DeferredTaxRightOfUseLiability_lbl" xml:lang="en-US"> Right-of-use liability </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_DeferredTaxRightOfUseAsset" xlink:label="OCX_DeferredTaxRightOfUseAsset"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DeferredTaxRightOfUseAsset" xlink:to="OCX_DeferredTaxRightOfUseAsset_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_DeferredTaxRightOfUseAsset_lbl" xml:lang="en-US"> Right-of-use asset </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredTaxAssetsGross" xlink:label="us-gaap_DeferredTaxAssetsGross"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsGross" xlink:to="us-gaap_DeferredTaxAssetsGross_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DeferredTaxAssetsGross_lbl" xml:lang="en-US"> Total </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsValuationAllowance" xlink:to="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xml:lang="en-US"> Valuation Allowance </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:to="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl" xml:lang="en-US"> Net deferred tax asset (liability) </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_2_lbl" xml:lang="en-US"> Computed tax benefit at federal statutory rate </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationDeductions" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationDeductions"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationDeductions" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationDeductions_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationDeductions_lbl" xml:lang="en-US"> Permanent differences </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" xml:lang="en-US"> State tax benefit </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch_lbl" xml:lang="en-US"> Research and development credits </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent_lbl" xml:lang="en-US"> Other </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_EffectiveIncomeTaxRateReconciliationAdjustBasisForAvailableforsalesecurities" xlink:label="OCX_EffectiveIncomeTaxRateReconciliationAdjustBasisForAvailableforsalesecurities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EffectiveIncomeTaxRateReconciliationAdjustBasisForAvailableforsalesecurities" xlink:to="OCX_EffectiveIncomeTaxRateReconciliationAdjustBasisForAvailableforsalesecurities_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_EffectiveIncomeTaxRateReconciliationAdjustBasisForAvailableforsalesecurities_lbl" xml:lang="en-US"> Adjust basis for available-for-sale-securities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl" xml:lang="en-US"> Change in valuation allowance </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:to="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xml:lang="en-US"> Income tax benefit percentage </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefits" xlink:to="us-gaap_UnrecognizedTaxBenefits_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_UnrecognizedTaxBenefits_2_lbl" xml:lang="en-US"> Balance at the beginning of the year </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_lbl" xml:lang="en-US"> Additions based on tax positions related to current year </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions" xlink:to="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_lbl" xml:lang="en-US"> Adjustments based on tax positions related to prior years </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefits" xlink:to="us-gaap_UnrecognizedTaxBenefits_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_UnrecognizedTaxBenefits_3_lbl" xml:lang="en-US"> Balance at end of year </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherCommitmentsTable" xlink:label="us-gaap_OtherCommitmentsTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherCommitmentsTable" xlink:to="us-gaap_OtherCommitmentsTable_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherCommitmentsTable_lbl" xml:lang="en-US"> Other Commitments [Table] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OtherCommitmentsLineItems" xlink:label="us-gaap_OtherCommitmentsLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_OtherCommitmentsLineItems_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherCommitmentsLineItems_lbl" xml:lang="en-US"> Other Commitments [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_AreaOfLand" xlink:label="us-gaap_AreaOfLand"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AreaOfLand" xlink:to="us-gaap_AreaOfLand_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AreaOfLand_lbl" xml:lang="en-US"> Area of land </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsForRent" xlink:label="us-gaap_PaymentsForRent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsForRent" xlink:to="us-gaap_PaymentsForRent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsForRent_lbl" xml:lang="en-US"> Payments for rent </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_CapitalLeaseAgreementImputedAnnualInterestRate" xlink:label="OCX_CapitalLeaseAgreementImputedAnnualInterestRate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_CapitalLeaseAgreementImputedAnnualInterestRate" xlink:to="OCX_CapitalLeaseAgreementImputedAnnualInterestRate_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_CapitalLeaseAgreementImputedAnnualInterestRate_lbl" xml:lang="en-US"> Interest rate on lease agreement </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ExpensesAndTaxesDescription" xlink:label="OCX_ExpensesAndTaxesDescription"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ExpensesAndTaxesDescription" xlink:to="OCX_ExpensesAndTaxesDescription_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ExpensesAndTaxesDescription_lbl" xml:lang="en-US"> Expenses and taxes description </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_PaymentsForProceedsFromTenantAllowance" xlink:label="us-gaap_PaymentsForProceedsFromTenantAllowance"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsForProceedsFromTenantAllowance" xlink:to="us-gaap_PaymentsForProceedsFromTenantAllowance_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsForProceedsFromTenantAllowance_lbl" xml:lang="en-US"> Payments of tenant improvement allowance </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_PercentageOfAdiministrativeFeePaidOnOriginalCostOfEquipment" xlink:label="OCX_PercentageOfAdiministrativeFeePaidOnOriginalCostOfEquipment"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PercentageOfAdiministrativeFeePaidOnOriginalCostOfEquipment" xlink:to="OCX_PercentageOfAdiministrativeFeePaidOnOriginalCostOfEquipment_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_PercentageOfAdiministrativeFeePaidOnOriginalCostOfEquipment_lbl" xml:lang="en-US"> Percentage of administrative fee paid on original cost of equipment </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SecurityDeposit" xlink:label="us-gaap_SecurityDeposit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SecurityDeposit" xlink:to="us-gaap_SecurityDeposit_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SecurityDeposit_lbl" xml:lang="en-US"> Security deposit </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LinesOfCreditCurrent" xlink:to="us-gaap_LinesOfCreditCurrent_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LinesOfCreditCurrent_2_lbl" xml:lang="en-US"> Line of credit </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasePayments" xlink:to="us-gaap_OperatingLeasePayments_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasePayments_2_lbl" xml:lang="en-US"> Lease payments </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_RoyaltyExpensesDescription" xlink:label="OCX_RoyaltyExpensesDescription"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RoyaltyExpensesDescription" xlink:to="OCX_RoyaltyExpensesDescription_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_RoyaltyExpensesDescription_lbl" xml:lang="en-US"> Royalty expenses description </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasePayments" xlink:to="us-gaap_OperatingLeasePayments_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeasePayments_3_lbl" xml:lang="en-US"> Operating cash flows from financing leases </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeasePrincipalPayments" xlink:to="us-gaap_FinanceLeasePrincipalPayments_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FinanceLeasePrincipalPayments_2_lbl" xml:lang="en-US"> Financing cash flows from financing leases </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:to="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_lbl" xml:lang="en-US"> Operating leases, including the Irvine Lease </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_PropertySubjectToOrAvailableForFinanceLeaseGross" xlink:label="OCX_PropertySubjectToOrAvailableForFinanceLeaseGross"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PropertySubjectToOrAvailableForFinanceLeaseGross" xlink:to="OCX_PropertySubjectToOrAvailableForFinanceLeaseGross_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_PropertySubjectToOrAvailableForFinanceLeaseGross_lbl" xml:lang="en-US"> Financing leases, Machinery and equipment, gross </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_AccumulatedDepreciationForfinanceLease" xlink:label="OCX_AccumulatedDepreciationForfinanceLease"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AccumulatedDepreciationForfinanceLease" xlink:to="OCX_AccumulatedDepreciationForfinanceLease_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_AccumulatedDepreciationForfinanceLease_lbl" xml:lang="en-US"> Financing leases, Accumulated depreciation </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_PropertyPlantAndEquipmentNetFinanceLease" xlink:label="OCX_PropertyPlantAndEquipmentNetFinanceLease"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PropertyPlantAndEquipmentNetFinanceLease" xlink:to="OCX_PropertyPlantAndEquipmentNetFinanceLease_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_PropertyPlantAndEquipmentNetFinanceLease_lbl" xml:lang="en-US"> Financing leases, Machinery and equipment, net </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeaseLiabilityCurrent" xlink:label="us-gaap_FinanceLeaseLiabilityCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityCurrent" xlink:to="us-gaap_FinanceLeaseLiabilityCurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FinanceLeaseLiabilityCurrent_lbl" xml:lang="en-US"> Current liabilities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:label="us-gaap_FinanceLeaseLiabilityNoncurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:to="us-gaap_FinanceLeaseLiabilityNoncurrent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FinanceLeaseLiabilityNoncurrent_lbl" xml:lang="en-US"> Noncurrent liabilities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeaseLiability" xlink:label="us-gaap_FinanceLeaseLiability"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiability" xlink:to="us-gaap_FinanceLeaseLiability_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FinanceLeaseLiability_lbl" xml:lang="en-US"> Total financing lease liabilities </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:to="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl" xml:lang="en-US"> Weighted average remaining lease term, Operating lease </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" xlink:label="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" xlink:to="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_lbl" xml:lang="en-US"> Weighted average remaining lease term, Financing leases </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:to="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_lbl" xml:lang="en-US"> Weighted average discount rate, Operating lease </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent" xlink:label="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent" xlink:to="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent_lbl" xml:lang="en-US"> Weighted average discount rate, Financing leases </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LeaseContractTypeAxis" xlink:to="OCX_LeaseContractTypeAxis_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="OCX_LeaseContractTypeAxis_2_lbl" xml:lang="en-US"> LeaseContractTypeAxis [Axis] </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xml:lang="en-US"> 2020 </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" xml:lang="en-US"> 2021 </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" xml:lang="en-US"> 2022 </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" xml:lang="en-US"> 2023 </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl" xml:lang="en-US"> 2024 </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl" xml:lang="en-US"> Thereafter </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl" xml:lang="en-US"> Total minimum lease payments </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" xml:lang="en-US"> Less amounts representing interest </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_LeasseeTenantImprovementAllowanceNetOfAdministrativeFee" xlink:label="OCX_LeasseeTenantImprovementAllowanceNetOfAdministrativeFee"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LeasseeTenantImprovementAllowanceNetOfAdministrativeFee" xlink:to="OCX_LeasseeTenantImprovementAllowanceNetOfAdministrativeFee_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_LeasseeTenantImprovementAllowanceNetOfAdministrativeFee_lbl" xml:lang="en-US"> Less: Tenant Improvement Allowance, net of administrative fee </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_OperatingLeaseLiability" xlink:label="us-gaap_OperatingLeaseLiability"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiability" xlink:to="us-gaap_OperatingLeaseLiability_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseLiability_lbl" xml:lang="en-US"> Present value of net minimum lease payments </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xml:lang="en-US"> 2020 </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_lbl" xml:lang="en-US"> 2021 </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_lbl" xml:lang="en-US"> 2022 </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour_lbl" xml:lang="en-US"> 2023 </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive_lbl" xml:lang="en-US"> 2024 </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive_lbl" xml:lang="en-US"> Thereafter </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDue" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDue" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDue_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDue_lbl" xml:lang="en-US"> Total minimum lease payments </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:label="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:to="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_lbl" xml:lang="en-US"> Less amounts representing interest </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_LeasseeFinancingTenantImprovementAllowanceNetOfAdministrativeFee" xlink:label="OCX_LeasseeFinancingTenantImprovementAllowanceNetOfAdministrativeFee"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LeasseeFinancingTenantImprovementAllowanceNetOfAdministrativeFee" xlink:to="OCX_LeasseeFinancingTenantImprovementAllowanceNetOfAdministrativeFee_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="OCX_LeasseeFinancingTenantImprovementAllowanceNetOfAdministrativeFee_lbl" xml:lang="en-US"> Less: Tenant Improvement Allowance, net of administrative fee </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiability" xlink:to="us-gaap_FinanceLeaseLiability_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FinanceLeaseLiability_2_lbl" xml:lang="en-US"> Present value of net minimum lease payments </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockNoParValue" xlink:to="us-gaap_CommonStockNoParValue_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockNoParValue_3_lbl" xml:lang="en-US"> Common stock, par value </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_SharePrice" xlink:label="us-gaap_SharePrice"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharePrice" xlink:to="us-gaap_SharePrice_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharePrice_lbl" xml:lang="en-US"> Share price </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodValueNewIssues_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_3_lbl" xml:lang="en-US"> Stock issued during the period, value </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_lbl" xml:lang="en-US"> Cash </link:label>
<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationConsiderationTransferred1" xlink:to="us-gaap_BusinessCombinationConsiderationTransferred1_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1_lbl" xml:lang="en-US"> Consideration transfered </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_BusinessCombinationNetCashHoldback" xlink:label="OCX_BusinessCombinationNetCashHoldback"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_BusinessCombinationNetCashHoldback" xlink:to="OCX_BusinessCombinationNetCashHoldback_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_BusinessCombinationNetCashHoldback_lbl" xml:lang="en-US"> Net cash holdback </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_StockHoldbackShareValue" xlink:label="OCX_StockHoldbackShareValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_StockHoldbackShareValue" xlink:to="OCX_StockHoldbackShareValue_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_StockHoldbackShareValue_lbl" xml:lang="en-US"> Stock holdback </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_PaymentsOfMilestone" xlink:label="OCX_PaymentsOfMilestone"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PaymentsOfMilestone" xlink:to="OCX_PaymentsOfMilestone_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_PaymentsOfMilestone_lbl" xml:lang="en-US"> Payments of milestone </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AccountingForSharesOfCommonStockPolicyTextBlock" xlink:to="OCX_AccountingForSharesOfCommonStockPolicyTextBlock_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_AccountingForSharesOfCommonStockPolicyTextBlock_doc" xml:lang="en-US"> Accounting for Biotime and Agex Shares of Common Stock [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_AccreditedInvestorOneMember" xlink:label="OCX_AccreditedInvestorOneMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AccreditedInvestorOneMember" xlink:to="OCX_AccreditedInvestorOneMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_AccreditedInvestorOneMember_doc" xml:lang="en-US"> Accredited Investor One [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AgeXTherapeuticsIncMember" xlink:to="OCX_AgeXTherapeuticsIncMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_AgeXTherapeuticsIncMember_doc" xml:lang="en-US"> AgeX Therapeutics, Inc [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AllocatedServicesAndFacilityUseFeePayable" xlink:to="OCX_AllocatedServicesAndFacilityUseFeePayable_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_AllocatedServicesAndFacilityUseFeePayable_doc" xml:lang="en-US"> The sum of amounts payable for charges to the entity by the parent company for services provided by the parent and for the shared use of a common facility under a "Shared Facilities and Services Agreement". The fees are allocated proportionally for costs incurred during the period by the entity. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AmortizationOfPrepaidMaintenance" xlink:to="OCX_AmortizationOfPrepaidMaintenance_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_AmortizationOfPrepaidMaintenance_doc" xml:lang="en-US"> Amortization of prepaid maintenance. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_BankWarrantMember" xlink:to="OCX_BankWarrantMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_BankWarrantMember_doc" xml:lang="en-US"> Bank Warrant [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_CommonStockSharesHeldAsAvailableForSaleSecurities" xlink:to="OCX_CommonStockSharesHeldAsAvailableForSaleSecurities_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_CommonStockSharesHeldAsAvailableForSaleSecurities_doc" xml:lang="en-US"> Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury) held by the entity as available for sale securities. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_CurrentLiabilitiesMember" xlink:to="OCX_CurrentLiabilitiesMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_CurrentLiabilitiesMember_doc" xml:lang="en-US"> Primary financial statement caption encompassing current liabilities. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DepositsAndOtherNoncurrentAssets" xlink:to="OCX_DepositsAndOtherNoncurrentAssets_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_DepositsAndOtherNoncurrentAssets_doc" xml:lang="en-US"> Deposits and other noncurrent assets. </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ExercisePriceRangeFourMember" xlink:label="OCX_ExercisePriceRangeFourMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ExercisePriceRangeFourMember" xlink:to="OCX_ExercisePriceRangeFourMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ExercisePriceRangeFourMember_doc" xml:lang="en-US"> Exercise Price Range Four [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ExercisePriceRangeOneMember" xlink:to="OCX_ExercisePriceRangeOneMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ExercisePriceRangeOneMember_doc" xml:lang="en-US"> Exercise Price Range One [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ExercisePriceRangeThreeMember" xlink:to="OCX_ExercisePriceRangeThreeMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ExercisePriceRangeThreeMember_doc" xml:lang="en-US"> Exercise Price Range Three [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ExercisePriceRangeTwoMember" xlink:to="OCX_ExercisePriceRangeTwoMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ExercisePriceRangeTwoMember_doc" xml:lang="en-US"> Exercise Price Range Two [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_FebruaryTwoThousandandNineteenMember" xlink:label="OCX_FebruaryTwoThousandandNineteenMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FebruaryTwoThousandandNineteenMember" xlink:to="OCX_FebruaryTwoThousandandNineteenMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_FebruaryTwoThousandandNineteenMember_doc" xml:lang="en-US"> February 2019 [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FederalMember" xlink:to="OCX_FederalMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_FederalMember_doc" xml:lang="en-US"> Federal [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FederalandStateMember" xlink:to="OCX_FederalandStateMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_FederalandStateMember_doc" xml:lang="en-US"> Federal and State [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_FirstFormWarrantExerciseAgreement2016WarrantsMember" xlink:label="OCX_FirstFormWarrantExerciseAgreement2016WarrantsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FirstFormWarrantExerciseAgreement2016WarrantsMember" xlink:to="OCX_FirstFormWarrantExerciseAgreement2016WarrantsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_FirstFormWarrantExerciseAgreement2016WarrantsMember_doc" xml:lang="en-US"> Name of the class or type of warrant or right outstanding. Warrants and rights represent derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_FirstFormWarrantExerciseAgreementJuly2017WarrantsMember" xlink:label="OCX_FirstFormWarrantExerciseAgreementJuly2017WarrantsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FirstFormWarrantExerciseAgreementJuly2017WarrantsMember" xlink:to="OCX_FirstFormWarrantExerciseAgreementJuly2017WarrantsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_FirstFormWarrantExerciseAgreementJuly2017WarrantsMember_doc" xml:lang="en-US"> Name of the class or type of warrant or right outstanding. Warrants and rights represent derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_InterestOnUnpaidOverdueInvoice" xlink:to="OCX_InterestOnUnpaidOverdueInvoice_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_InterestOnUnpaidOverdueInvoice_doc" xml:lang="en-US"> Represents the percentage of interest charged on invoices not paid when due. </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_InvestorsGroupOneMember" xlink:label="OCX_InvestorsGroupOneMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_InvestorsGroupOneMember" xlink:to="OCX_InvestorsGroupOneMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_InvestorsGroupOneMember_doc" xml:lang="en-US"> Refers to investors who exercised warrants. </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_July2017WarrantsMember" xlink:label="OCX_July2017WarrantsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_July2017WarrantsMember" xlink:to="OCX_July2017WarrantsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_July2017WarrantsMember_doc" xml:lang="en-US"> Refers to security that gives the holder the right to purchase shares of stock in accordance with the terms of the instrument, usually upon payment of a specified amount issued during July 2017. </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_JulyThirtyOneTwoThousandEighteenMember" xlink:label="OCX_JulyThirtyOneTwoThousandEighteenMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_JulyThirtyOneTwoThousandEighteenMember" xlink:to="OCX_JulyThirtyOneTwoThousandEighteenMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_JulyThirtyOneTwoThousandEighteenMember_doc" xml:lang="en-US"> July 31, 2018 [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_JulyTwoThousandEighteenOfferingWarrantsMember" xlink:label="OCX_JulyTwoThousandEighteenOfferingWarrantsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_JulyTwoThousandEighteenOfferingWarrantsMember" xlink:to="OCX_JulyTwoThousandEighteenOfferingWarrantsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_JulyTwoThousandEighteenOfferingWarrantsMember_doc" xml:lang="en-US"> July 2018 Offering Warrants [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LaboratoryEquipmentMember" xlink:to="OCX_LaboratoryEquipmentMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_LaboratoryEquipmentMember_doc" xml:lang="en-US"> Laboratory Equipment [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LoanAndSecurityAgreementMember" xlink:to="OCX_LoanAndSecurityAgreementMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_LoanAndSecurityAgreementMember_doc" xml:lang="en-US"> Refers to information about a contractual promise to repay a long-term obligation, which includes borrowings under a notes payable contractual obligations for payment. </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_LoanPayableMember" xlink:label="OCX_LoanPayableMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LoanPayableMember" xlink:to="OCX_LoanPayableMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_LoanPayableMember_doc" xml:lang="en-US"> Loan Payable [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_MayTenThousandEighteenMember" xlink:label="OCX_MayTenThousandEighteenMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_MayTenThousandEighteenMember" xlink:to="OCX_MayTenThousandEighteenMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_MayTenThousandEighteenMember_doc" xml:lang="en-US"> May 10, 2018 [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_NewWarrantsMember" xlink:label="OCX_NewWarrantsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_NewWarrantsMember" xlink:to="OCX_NewWarrantsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_NewWarrantsMember_doc" xml:lang="en-US"> Name of the class or type of warrant or right outstanding. Warrants and rights represent derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_NumberOfCommonStockSharesAvailableInEachSeparableUnit" xlink:to="OCX_NumberOfCommonStockSharesAvailableInEachSeparableUnit_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_NumberOfCommonStockSharesAvailableInEachSeparableUnit_doc" xml:lang="en-US"> Refers to the number of common shares included in each immediate separable unit issued. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_NumberOfWarrantsAvailableInEachSeparableUnit" xlink:to="OCX_NumberOfWarrantsAvailableInEachSeparableUnit_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_NumberOfWarrantsAvailableInEachSeparableUnit_doc" xml:lang="en-US"> Refers to the number of warrants for common shares included in each separable unit issued. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PercentageOfMarkupFeeAllocatedButNotCharged" xlink:to="OCX_PercentageOfMarkupFeeAllocatedButNotCharged_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_PercentageOfMarkupFeeAllocatedButNotCharged_doc" xml:lang="en-US"> The percentage markup of the fee for the services and usage of facilities, equipment, and supplies aforementioned which shall be paid by the entity under Shared Facilities Agreement. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SalesAndMarketingCostsPolicyTextBlock" xlink:to="OCX_SalesAndMarketingCostsPolicyTextBlock_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_SalesAndMarketingCostsPolicyTextBlock_doc" xml:lang="en-US"> Disclosure of accounting policy for the recognition of sales and marketing costs [Policy Text Block] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ScheduleOfAccruedExpensesAndOtherCurrentLiabilitiesTableTextBlock" xlink:to="OCX_ScheduleOfAccruedExpensesAndOtherCurrentLiabilitiesTableTextBlock_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ScheduleOfAccruedExpensesAndOtherCurrentLiabilitiesTableTextBlock_doc" xml:lang="en-US"> Schedule of Accrued Expenses and Other Current Liabilities [Table Text Block] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ScheduleOfAggregateUseOfFeesChargedTableTextBlock" xlink:to="OCX_ScheduleOfAggregateUseOfFeesChargedTableTextBlock_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ScheduleOfAggregateUseOfFeesChargedTableTextBlock_doc" xml:lang="en-US"> Schedule of aggregate use of fees charged [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_SecondFormWarrantExerciseAgreement2016WarrantsMember" xlink:label="OCX_SecondFormWarrantExerciseAgreement2016WarrantsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SecondFormWarrantExerciseAgreement2016WarrantsMember" xlink:to="OCX_SecondFormWarrantExerciseAgreement2016WarrantsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_SecondFormWarrantExerciseAgreement2016WarrantsMember_doc" xml:lang="en-US"> Name of the class or type of warrant or right outstanding. Warrants and rights represent derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_SecondFormWarrantExerciseAgreementJuly2017WarrantMember" xlink:label="OCX_SecondFormWarrantExerciseAgreementJuly2017WarrantMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SecondFormWarrantExerciseAgreementJuly2017WarrantMember" xlink:to="OCX_SecondFormWarrantExerciseAgreementJuly2017WarrantMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_SecondFormWarrantExerciseAgreementJuly2017WarrantMember_doc" xml:lang="en-US"> Second Form, Warrant Exercise Agreement, July 2017 Warrant [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_SecondFormWarrantExerciseAgreementJuly2017WarrantsMember" xlink:label="OCX_SecondFormWarrantExerciseAgreementJuly2017WarrantsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SecondFormWarrantExerciseAgreementJuly2017WarrantsMember" xlink:to="OCX_SecondFormWarrantExerciseAgreementJuly2017WarrantsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_SecondFormWarrantExerciseAgreementJuly2017WarrantsMember_doc" xml:lang="en-US"> Name of the class or type of warrant or right outstanding. Warrants and rights represent derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_SecondFormWarrantExerciseAgreementJulyTwoThousandAndSeventeenWarrantMember" xlink:label="OCX_SecondFormWarrantExerciseAgreementJulyTwoThousandAndSeventeenWarrantMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SecondFormWarrantExerciseAgreementJulyTwoThousandAndSeventeenWarrantMember" xlink:to="OCX_SecondFormWarrantExerciseAgreementJulyTwoThousandAndSeventeenWarrantMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_SecondFormWarrantExerciseAgreementJulyTwoThousandAndSeventeenWarrantMember_doc" xml:lang="en-US"> Second Form, Warrant Exercise Agreement, July 2017 Warrant [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SecuritiesPurchaseAgreementMember" xlink:to="OCX_SecuritiesPurchaseAgreementMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_SecuritiesPurchaseAgreementMember_doc" xml:lang="en-US"> Securities Purchase Agreement [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SharedFacilitiesAgreementMember" xlink:to="OCX_SharedFacilitiesAgreementMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_SharedFacilitiesAgreementMember_doc" xml:lang="en-US"> Shared Facilities Agreement [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_StateMember" xlink:to="OCX_StateMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_StateMember_doc" xml:lang="en-US"> State [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_StockOptionsMember" xlink:to="OCX_StockOptionsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_StockOptionsMember_doc" xml:lang="en-US"> Stock Options [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_TermOfPayment" xlink:to="OCX_TermOfPayment_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_TermOfPayment_doc" xml:lang="en-US"> Represents the maximum number of days upon the receipt of an invoice within which the invoice must be paid, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ThirdFormPart1WarrantExerciseAgreementJulyTwoThousandSeventeenWarrantMember" xlink:label="OCX_ThirdFormPart1WarrantExerciseAgreementJulyTwoThousandSeventeenWarrantMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ThirdFormPart1WarrantExerciseAgreementJulyTwoThousandSeventeenWarrantMember" xlink:to="OCX_ThirdFormPart1WarrantExerciseAgreementJulyTwoThousandSeventeenWarrantMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ThirdFormPart1WarrantExerciseAgreementJulyTwoThousandSeventeenWarrantMember_doc" xml:lang="en-US"> Third Form Part1 Warrant Exercise Agreement July 2017 Warrant [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ThirdFormPart2WarrantExerciseAgreementJulyTwoThousandSeventeenWarrantMember" xlink:label="OCX_ThirdFormPart2WarrantExerciseAgreementJulyTwoThousandSeventeenWarrantMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ThirdFormPart2WarrantExerciseAgreementJulyTwoThousandSeventeenWarrantMember" xlink:to="OCX_ThirdFormPart2WarrantExerciseAgreementJulyTwoThousandSeventeenWarrantMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ThirdFormPart2WarrantExerciseAgreementJulyTwoThousandSeventeenWarrantMember_doc" xml:lang="en-US"> Third Form Part2 Warrant Exercise Agreement July 2017 Warrant [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ThirdFormWarrantExerciseAgreement2016WarrantsMember" xlink:label="OCX_ThirdFormWarrantExerciseAgreement2016WarrantsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ThirdFormWarrantExerciseAgreement2016WarrantsMember" xlink:to="OCX_ThirdFormWarrantExerciseAgreement2016WarrantsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ThirdFormWarrantExerciseAgreement2016WarrantsMember_doc" xml:lang="en-US"> Name of the class or type of warrant or right outstanding. Warrants and rights represent derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_TwoAccreditedInvestorsMember" xlink:to="OCX_TwoAccreditedInvestorsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_TwoAccreditedInvestorsMember_doc" xml:lang="en-US"> Two Accredited Investors [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_TwoThousandEighteenPalnActivityMember" xlink:to="OCX_TwoThousandEighteenPalnActivityMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_TwoThousandEighteenPalnActivityMember_doc" xml:lang="en-US"> 2018 Incentive Plan Activity [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_TwoThousandEighteenPlanMember" xlink:label="OCX_TwoThousandEighteenPlanMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_TwoThousandEighteenPlanMember" xlink:to="OCX_TwoThousandEighteenPlanMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_TwoThousandEighteenPlanMember_doc" xml:lang="en-US"> 2018 Incentive Plan [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_TwoThousandSixteenWarrantsAndNewWarrantsMember" xlink:label="OCX_TwoThousandSixteenWarrantsAndNewWarrantsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_TwoThousandSixteenWarrantsAndNewWarrantsMember" xlink:to="OCX_TwoThousandSixteenWarrantsAndNewWarrantsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_TwoThousandSixteenWarrantsAndNewWarrantsMember_doc" xml:lang="en-US"> 2016 Warrants and New Warrants [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_TwoThousandSixteenWarrantsMember" xlink:label="OCX_TwoThousandSixteenWarrantsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_TwoThousandSixteenWarrantsMember" xlink:to="OCX_TwoThousandSixteenWarrantsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_TwoThousandSixteenWarrantsMember_doc" xml:lang="en-US"> 2016 Warrants [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_TwoThousandTenPalnActivityMember" xlink:to="OCX_TwoThousandTenPalnActivityMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_TwoThousandTenPalnActivityMember_doc" xml:lang="en-US"> 2010 Plan Activity [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_TwoThousandTenStockOptionPlanMember" xlink:to="OCX_TwoThousandTenStockOptionPlanMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_TwoThousandTenStockOptionPlanMember_doc" xml:lang="en-US"> 2010 Stock Option Plan [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_UseFees" xlink:to="OCX_UseFees_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_UseFees_doc" xml:lang="en-US"> Use fees. </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_Warrants2016Member" xlink:label="OCX_Warrants2016Member"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_Warrants2016Member" xlink:to="OCX_Warrants2016Member_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_Warrants2016Member_doc" xml:lang="en-US"> Name of the class or type of warrant or right outstanding. Warrants and rights represent derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PaymentsToSecurityDepositAndOther" xlink:to="OCX_PaymentsToSecurityDepositAndOther_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_PaymentsToSecurityDepositAndOther_doc" xml:lang="en-US"> Security deposit and other. </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_WilliamAnnettMember" xlink:label="OCX_WilliamAnnettMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_WilliamAnnettMember" xlink:to="OCX_WilliamAnnettMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_WilliamAnnettMember_doc" xml:lang="en-US"> William Annett [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_TwoInvestorsMember" xlink:label="OCX_TwoInvestorsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_TwoInvestorsMember" xlink:to="OCX_TwoInvestorsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_TwoInvestorsMember_doc" xml:lang="en-US"> Two Investors [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_ThirdFormPart1WarrantExerciseAgreementJulyTwoThousandSeventeenWarrantOneMember" xlink:label="OCX_ThirdFormPart1WarrantExerciseAgreementJulyTwoThousandSeventeenWarrantOneMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ThirdFormPart1WarrantExerciseAgreementJulyTwoThousandSeventeenWarrantOneMember" xlink:to="OCX_ThirdFormPart1WarrantExerciseAgreementJulyTwoThousandSeventeenWarrantOneMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ThirdFormPart1WarrantExerciseAgreementJulyTwoThousandSeventeenWarrantOneMember_doc" xml:lang="en-US"> Third Form Part1 Warrant Exercise Agreement July 2017 Warrant [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EmployeesAndConsultantsMember" xlink:to="OCX_EmployeesAndConsultantsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_EmployeesAndConsultantsMember_doc" xml:lang="en-US"> Employees and Consultants [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PerformanceBasedOptionsMember" xlink:to="OCX_PerformanceBasedOptionsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_PerformanceBasedOptionsMember_doc" xml:lang="en-US"> Performance-Based Options [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EmployeesMember" xlink:to="OCX_EmployeesMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_EmployeesMember_doc" xml:lang="en-US"> Employees [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_EmploymentAgreementMember" xlink:label="OCX_EmploymentAgreementMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EmploymentAgreementMember" xlink:to="OCX_EmploymentAgreementMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_EmploymentAgreementMember_doc" xml:lang="en-US"> Employment Agreement [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_TerminationAgreementMember" xlink:label="OCX_TerminationAgreementMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_TerminationAgreementMember" xlink:to="OCX_TerminationAgreementMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_TerminationAgreementMember_doc" xml:lang="en-US"> Termination Agreement [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_SeveranceBenefitsMember" xlink:label="OCX_SeveranceBenefitsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SeveranceBenefitsMember" xlink:to="OCX_SeveranceBenefitsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_SeveranceBenefitsMember_doc" xml:lang="en-US"> Severance Benefits [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ProceedsFromSaleOfCommonStockAndWarrants" xlink:to="OCX_ProceedsFromSaleOfCommonStockAndWarrants_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ProceedsFromSaleOfCommonStockAndWarrants_doc" xml:lang="en-US"> Proceeds from sale of common shares and warrants. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FinancingCostsToIssueCommonSharesAndWarrants" xlink:to="OCX_FinancingCostsToIssueCommonSharesAndWarrants_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_FinancingCostsToIssueCommonSharesAndWarrants_doc" xml:lang="en-US"> Financing costs to issue common shares and warrants. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_OperatingAndFinanceLeaseCashFlowTableTextBlock" xlink:to="OCX_OperatingAndFinanceLeaseCashFlowTableTextBlock_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_OperatingAndFinanceLeaseCashFlowTableTextBlock_doc" xml:lang="en-US"> Schedule of Supplemental Cash Flow Information Related to Operating and Financing Lease [Table Text Block] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_OperatingAndFinanceLeaseBalanceSheetTableTextBlock" xlink:to="OCX_OperatingAndFinanceLeaseBalanceSheetTableTextBlock_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_OperatingAndFinanceLeaseBalanceSheetTableTextBlock_doc" xml:lang="en-US"> Schedule of Supplemental Balance Sheet Information Related to Financing Leases [Table Text Block] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RazorGenomicsIncMember" xlink:to="OCX_RazorGenomicsIncMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_RazorGenomicsIncMember_doc" xml:lang="en-US"> Razor Genomics, Inc. [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EquityMethodInvestmentDescription" xlink:to="OCX_EquityMethodInvestmentDescription_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_EquityMethodInvestmentDescription_doc" xml:lang="en-US"> Equity method investment, description. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_BroadwoodPartnersLPAndGeorgeKarfunkelMember" xlink:to="OCX_BroadwoodPartnersLPAndGeorgeKarfunkelMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_BroadwoodPartnersLPAndGeorgeKarfunkelMember_doc" xml:lang="en-US"> Broadwood Partners, L.P. and George Karfunkel [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SeriesAConvertiblePreferredStockMember" xlink:to="OCX_SeriesAConvertiblePreferredStockMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_SeriesAConvertiblePreferredStockMember_doc" xml:lang="en-US"> Series A Convertible Preferred Stock [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_NumberOfSharesPurchased" xlink:to="OCX_NumberOfSharesPurchased_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_NumberOfSharesPurchased_doc" xml:lang="en-US"> Number of shares purchased. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PurchaseAgreementMember" xlink:to="OCX_PurchaseAgreementMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_PurchaseAgreementMember_doc" xml:lang="en-US"> Purchase Agreement [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ClinicalTrialExpenseReserveAmount" xlink:to="OCX_ClinicalTrialExpenseReserveAmount_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ClinicalTrialExpenseReserveAmount_doc" xml:lang="en-US"> Clinical trial expense reserve amount. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DevelopmentAgreementMember" xlink:to="OCX_DevelopmentAgreementMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_DevelopmentAgreementMember_doc" xml:lang="en-US"> Development Agreement [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_MilestonePayment" xlink:to="OCX_MilestonePayment_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_MilestonePayment_doc" xml:lang="en-US"> Milestone payment. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EncoreClinicalIncMember" xlink:to="OCX_EncoreClinicalIncMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_EncoreClinicalIncMember_doc" xml:lang="en-US"> Encore Clinical, Inc. [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_MilestonePaymentDescription" xlink:to="OCX_MilestonePaymentDescription_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_MilestonePaymentDescription_doc" xml:lang="en-US"> Milestone payment description. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PaymentObligationAmount" xlink:to="OCX_PaymentObligationAmount_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_PaymentObligationAmount_doc" xml:lang="en-US"> Payment obligation amount. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LaboratoryAgreementMember" xlink:to="OCX_LaboratoryAgreementMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_LaboratoryAgreementMember_doc" xml:lang="en-US"> Laboratory Agreement [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AmendedLoanAgreementMember" xlink:to="OCX_AmendedLoanAgreementMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_AmendedLoanAgreementMember_doc" xml:lang="en-US"> Amended Loan Agreement [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PreliminaryCoverageMilestonePayment" xlink:to="OCX_PreliminaryCoverageMilestonePayment_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_PreliminaryCoverageMilestonePayment_doc" xml:lang="en-US"> Preliminary coverage milestone payment. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RecentlyIssuedAccountingPronouncementsNotYetAdoptedPolicyTextBlock" xlink:to="OCX_RecentlyIssuedAccountingPronouncementsNotYetAdoptedPolicyTextBlock_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_RecentlyIssuedAccountingPronouncementsNotYetAdoptedPolicyTextBlock_doc" xml:lang="en-US"> Recently issued accounting pronouncements not yet adopted [Policy Text Block] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_CommonStockAndWarrantsMember" xlink:to="OCX_CommonStockAndWarrantsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_CommonStockAndWarrantsMember_doc" xml:lang="en-US"> Common Stock and Warrants [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_JulyTwoThousandEighteenOfferingMember" xlink:to="OCX_JulyTwoThousandEighteenOfferingMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_JulyTwoThousandEighteenOfferingMember_doc" xml:lang="en-US"> July 2018 Offering [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RonaldAndrewsMember" xlink:to="OCX_RonaldAndrewsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_RonaldAndrewsMember_doc" xml:lang="en-US"> Ronald Andrews [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ScheduleOfFutureMinimumLeaseCommitmentsForOperatingAndFinancingLeasesTableTextBlock" xlink:to="OCX_ScheduleOfFutureMinimumLeaseCommitmentsForOperatingAndFinancingLeasesTableTextBlock_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ScheduleOfFutureMinimumLeaseCommitmentsForOperatingAndFinancingLeasesTableTextBlock_doc" xml:lang="en-US"> Schedule of Future Minimum Lease Commitments for Operating and Financing Leases [Table Text Block] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EstimatedClinicalTrialExpense" xlink:to="OCX_EstimatedClinicalTrialExpense_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_EstimatedClinicalTrialExpense_doc" xml:lang="en-US"> Estimated clinical trial expense. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_WriteOffInDepreciatedAssets" xlink:to="OCX_WriteOffInDepreciatedAssets_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_WriteOffInDepreciatedAssets_doc" xml:lang="en-US"> Write off in depreciated assets. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_StockPurchaseAgreementsMember" xlink:to="OCX_StockPurchaseAgreementsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_StockPurchaseAgreementsMember_doc" xml:lang="en-US"> Stock Purchase Agreements [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_NewMachineryandEquipmentMember" xlink:label="OCX_NewMachineryandEquipmentMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_NewMachineryandEquipmentMember" xlink:to="OCX_NewMachineryandEquipmentMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_NewMachineryandEquipmentMember_doc" xml:lang="en-US"> New Machinery and Equipment [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RightofuseAssetsMachineryAndEquipmentNet" xlink:to="OCX_RightofuseAssetsMachineryAndEquipmentNet_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_RightofuseAssetsMachineryAndEquipmentNet_doc" xml:lang="en-US"> Right-of-use assets, machinery and equipment, net. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RightofuseAndFinancingLeaseLiabilitiesCurrent" xlink:to="OCX_RightofuseAndFinancingLeaseLiabilitiesCurrent_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_RightofuseAndFinancingLeaseLiabilitiesCurrent_doc" xml:lang="en-US"> Right-of-use and financing lease liabilities, current. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RightofuseAndFinancingLeaseLiabilitiesNoncurrent" xlink:to="OCX_RightofuseAndFinancingLeaseLiabilitiesNoncurrent_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_RightofuseAndFinancingLeaseLiabilitiesNoncurrent_doc" xml:lang="en-US"> Right-of-use and financing lease liabilities, noncurrent. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AmortizationOfRightOfUseAssetsAndLiabilities" xlink:to="OCX_AmortizationOfRightOfUseAssetsAndLiabilities_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_AmortizationOfRightOfUseAssetsAndLiabilities_doc" xml:lang="en-US"> Amortization of right of use assets and liabilities. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RepaymentsOfPrincipalAndBankFeesFromRefinancingOfBankLoan" xlink:to="OCX_RepaymentsOfPrincipalAndBankFeesFromRefinancingOfBankLoan_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_RepaymentsOfPrincipalAndBankFeesFromRefinancingOfBankLoan_doc" xml:lang="en-US"> Repayments of principal and bank fees from refinancing of bank loan. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DeferredFinalCommitmentFeeForBankLoan" xlink:to="OCX_DeferredFinalCommitmentFeeForBankLoan_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_DeferredFinalCommitmentFeeForBankLoan_doc" xml:lang="en-US"> Deferred final commitment fee for bank loan. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EquipmentPurchasedUnderFinancingLeases" xlink:to="OCX_EquipmentPurchasedUnderFinancingLeases_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_EquipmentPurchasedUnderFinancingLeases_doc" xml:lang="en-US"> Equipment purchased under financing leases. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_StockIssuedDuringPeriodSharesIssuanceOfWarrants" xlink:to="OCX_StockIssuedDuringPeriodSharesIssuanceOfWarrants_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_StockIssuedDuringPeriodSharesIssuanceOfWarrants_doc" xml:lang="en-US"> Stock issued during period shares issuance of warrants. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_GoingConcernAssessmentPolicyTextBlock" xlink:to="OCX_GoingConcernAssessmentPolicyTextBlock_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_GoingConcernAssessmentPolicyTextBlock_doc" xml:lang="en-US"> Going Concern Assessment [Policy Text Block] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AccountingForWarrantsPolicyTextBlock" xlink:to="OCX_AccountingForWarrantsPolicyTextBlock_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_AccountingForWarrantsPolicyTextBlock_doc" xml:lang="en-US"> Accounting for Warrants [Policy Text Block] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SchduleOfStockOptionsOutstandingVestedAndExercisableTableTextBlock" xlink:to="OCX_SchduleOfStockOptionsOutstandingVestedAndExercisableTableTextBlock_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_SchduleOfStockOptionsOutstandingVestedAndExercisableTableTextBlock_doc" xml:lang="en-US"> Schdule of Stock Options Outstanding, Vested and Exercisable [Table Text Block] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EquityDistributionAgreementMember" xlink:to="OCX_EquityDistributionAgreementMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_EquityDistributionAgreementMember_doc" xml:lang="en-US"> Equity Distribution Agreement [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PiperSandlerAndCoMember" xlink:to="OCX_PiperSandlerAndCoMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_PiperSandlerAndCoMember_doc" xml:lang="en-US"> Piper Sandler & Co [Member] </link:label>
<link:loc xlink:type="locator" xlink:href="ocx-20191231.xsd#OCX_LineageCellTherapeuticsIncMember" xlink:label="OCX_LineageCellTherapeuticsIncMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LineageCellTherapeuticsIncMember" xlink:to="OCX_LineageCellTherapeuticsIncMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_LineageCellTherapeuticsIncMember_doc" xml:lang="en-US"> Lineage Cell Therapeutics, Inc [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_IntangibleAssetsNoncashCharge" xlink:to="OCX_IntangibleAssetsNoncashCharge_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_IntangibleAssetsNoncashCharge_doc" xml:lang="en-US"> Intangible assets noncash charge. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FinancingLeaseObligation" xlink:to="OCX_FinancingLeaseObligation_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_FinancingLeaseObligation_doc" xml:lang="en-US"> Financing lease obligation. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PrepaidVendorsDepositsAndServiceAgreements" xlink:to="OCX_PrepaidVendorsDepositsAndServiceAgreements_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_PrepaidVendorsDepositsAndServiceAgreements_doc" xml:lang="en-US"> Prepaid vendors, deposits and service agreements. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_BroadwoodPartnersLPMember" xlink:to="OCX_BroadwoodPartnersLPMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_BroadwoodPartnersLPMember_doc" xml:lang="en-US"> Broadwood Partners, L.P [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RestrictedCashAndSecurityDepositForLease" xlink:to="OCX_RestrictedCashAndSecurityDepositForLease_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_RestrictedCashAndSecurityDepositForLease_doc" xml:lang="en-US"> Restricted cash and security deposit for lease. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RestrictedCashIncludedInDepositsAndOtherNoncurrentAssets" xlink:to="OCX_RestrictedCashIncludedInDepositsAndOtherNoncurrentAssets_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_RestrictedCashIncludedInDepositsAndOtherNoncurrentAssets_doc" xml:lang="en-US"> Restricted cash included in deposits and other noncurrent assets. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LeaseTermDescription" xlink:to="OCX_LeaseTermDescription_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_LeaseTermDescription_doc" xml:lang="en-US"> Lease term description. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ScheduleOfReconciliationOfCashCashEquivalentsAndRestrictedCashTableTextBlock" xlink:to="OCX_ScheduleOfReconciliationOfCashCashEquivalentsAndRestrictedCashTableTextBlock_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ScheduleOfReconciliationOfCashCashEquivalentsAndRestrictedCashTableTextBlock_doc" xml:lang="en-US"> Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash [Table Text Block] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_CumulativeEffectOfAdjustmentForAdoptionOnAccumulatedOtherComprehensiveLoss" xlink:to="OCX_CumulativeEffectOfAdjustmentForAdoptionOnAccumulatedOtherComprehensiveLoss_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_CumulativeEffectOfAdjustmentForAdoptionOnAccumulatedOtherComprehensiveLoss_doc" xml:lang="en-US"> Cumulative effect of adjustment for adoption on accumulated other comprehensive loss. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PrepaymentFeeIfPrepaidTwoYearsOrMore" xlink:to="OCX_PrepaymentFeeIfPrepaidTwoYearsOrMore_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_PrepaymentFeeIfPrepaidTwoYearsOrMore_doc" xml:lang="en-US"> Refers to percentage of the outstanding principal balance to be paid as prepayment fee if prepaid two years or more after the effective date. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DebtDefaultLegalActionAmount" xlink:to="OCX_DebtDefaultLegalActionAmount_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_DebtDefaultLegalActionAmount_doc" xml:lang="en-US"> Refers to the amount necessary to trigger a default of the loan agreement caused by legal judgments, or pending or threatened legal actions against the entity per the debt covenant. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DilutedEquityOutstanding" xlink:to="OCX_DilutedEquityOutstanding_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_DilutedEquityOutstanding_doc" xml:lang="en-US"> Diluted equity outstanding. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PaymentsOfPrincipalAndInterest" xlink:to="OCX_PaymentsOfPrincipalAndInterest_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_PaymentsOfPrincipalAndInterest_doc" xml:lang="en-US"> Payments of principal and interest. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LoanPayableAmountsRepresentingInterest" xlink:to="OCX_LoanPayableAmountsRepresentingInterest_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_LoanPayableAmountsRepresentingInterest_doc" xml:lang="en-US"> Loan payable amounts representing interest. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_CommonStockPurchaseWarrantsSharesIssued" xlink:to="OCX_CommonStockPurchaseWarrantsSharesIssued_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_CommonStockPurchaseWarrantsSharesIssued_doc" xml:lang="en-US"> Common stock purchase warrants, shares issued. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FairMarketValueOfCommonStockPercentage" xlink:to="OCX_FairMarketValueOfCommonStockPercentage_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_FairMarketValueOfCommonStockPercentage_doc" xml:lang="en-US"> Fair market value of common stock percentage. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedOptionPoolIncrease" xlink:to="OCX_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedOptionPoolIncrease_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedOptionPoolIncrease_doc" xml:lang="en-US"> Share based compensation arrangement by share based payment award options vested option pool increase. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableGrantsInPeriodGross" xlink:to="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableGrantsInPeriodGross_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableGrantsInPeriodGross_doc" xml:lang="en-US"> Gross number of share options (or share units) granted during the period. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableRestrictedStockOptionsGrantsInPeriodGross" xlink:to="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableRestrictedStockOptionsGrantsInPeriodGross_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableRestrictedStockOptionsGrantsInPeriodGross_doc" xml:lang="en-US"> Shares Available For Grant Options RSUs Granted. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SharesAvailableForGrantOptionsTermination" xlink:to="OCX_SharesAvailableForGrantOptionsTermination_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_SharesAvailableForGrantOptionsTermination_doc" xml:lang="en-US"> Shares Available for Grant Options, Termination of the 2010 Plan. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_NumberOfOptionsOutstandingApprovalOfTwoThousandEighteenIncentivePlan" xlink:to="OCX_NumberOfOptionsOutstandingApprovalOfTwoThousandEighteenIncentivePlan_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_NumberOfOptionsOutstandingApprovalOfTwoThousandEighteenIncentivePlan_doc" xml:lang="en-US"> Number Of Options Outstanding, Approval of 2018 Incentive Plan. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionPoolIncrease" xlink:to="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionPoolIncrease_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionPoolIncrease_doc" xml:lang="en-US"> Share based compensation arrangement by share based payment award option pool increase. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodGross" xlink:to="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodGross_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodGross_doc" xml:lang="en-US"> Number Of Options Outstanding, Option RSUs Granted. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_NumberOfOptionsOutstandingTermination" xlink:to="OCX_NumberOfOptionsOutstandingTermination_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_NumberOfOptionsOutstandingTermination_doc" xml:lang="en-US"> Number Of Options Outstanding, Termination of The 2010 Plan. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_WeightedAverageExercisePriceApprovalOfTwoThousandEighteenIncentivePlan" xlink:to="OCX_WeightedAverageExercisePriceApprovalOfTwoThousandEighteenIncentivePlan_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_WeightedAverageExercisePriceApprovalOfTwoThousandEighteenIncentivePlan_doc" xml:lang="en-US"> Weighted Average Exercise Price, Approval of 2018 Incentive Plan. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsPoolIncreaseInPeriodWeightedAverageExercisePrice" xlink:to="OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsPoolIncreaseInPeriodWeightedAverageExercisePrice_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsPoolIncreaseInPeriodWeightedAverageExercisePrice_doc" xml:lang="en-US"> Weighted average exercise price, option pool increase. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:to="OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodWeightedAverageExercisePrice_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ShareBasedCompensationArrangementsByShareBasedPaymentAwardRestrictedStockOptionsGrantsInPeriodWeightedAverageExercisePrice_doc" xml:lang="en-US"> Weighted Average Exercise Price, Option RSUs Granted. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_WeightedAverageExercisePriceOptionsTermination" xlink:to="OCX_WeightedAverageExercisePriceOptionsTermination_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_WeightedAverageExercisePriceOptionsTermination_doc" xml:lang="en-US"> Weighted Average Exercise Price, Options Termination of the 2010 Plan. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_NetOperatingLossExpirationPeriodDescription" xlink:to="OCX_NetOperatingLossExpirationPeriodDescription_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_NetOperatingLossExpirationPeriodDescription_doc" xml:lang="en-US"> Net operating loss expiration period description. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_CreditCarryforwardExpirationTerm" xlink:to="OCX_CreditCarryforwardExpirationTerm_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_CreditCarryforwardExpirationTerm_doc" xml:lang="en-US"> Credit carryforward expiration term. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DeferredTaxAssetsPatentsAndFixedAssets" xlink:to="OCX_DeferredTaxAssetsPatentsAndFixedAssets_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_DeferredTaxAssetsPatentsAndFixedAssets_doc" xml:lang="en-US"> Patents and fixed assets. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DeferredTaxRightOfUseLiability" xlink:to="OCX_DeferredTaxRightOfUseLiability_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_DeferredTaxRightOfUseLiability_doc" xml:lang="en-US"> Right-of-use liability. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DeferredTaxRightOfUseAsset" xlink:to="OCX_DeferredTaxRightOfUseAsset_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_DeferredTaxRightOfUseAsset_doc" xml:lang="en-US"> Right-of-use asset. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_EffectiveIncomeTaxRateReconciliationAdjustBasisForAvailableforsalesecurities" xlink:to="OCX_EffectiveIncomeTaxRateReconciliationAdjustBasisForAvailableforsalesecurities_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_EffectiveIncomeTaxRateReconciliationAdjustBasisForAvailableforsalesecurities_doc" xml:lang="en-US"> Effective income tax rate reconciliation adjust basis for available-for-sale-securities. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_OfficeLeaseAgreementMember" xlink:to="OCX_OfficeLeaseAgreementMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_OfficeLeaseAgreementMember_doc" xml:lang="en-US"> Office Lease Agreement [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_MonthlyRentMember" xlink:to="OCX_MonthlyRentMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_MonthlyRentMember_doc" xml:lang="en-US"> Monthly Rent [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FirstTenCalendarMember" xlink:to="OCX_FirstTenCalendarMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_FirstTenCalendarMember_doc" xml:lang="en-US"> First Ten Calendar [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LandlordMember" xlink:to="OCX_LandlordMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_LandlordMember_doc" xml:lang="en-US"> Landlord [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LicenseAgreementMember" xlink:to="OCX_LicenseAgreementMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_LicenseAgreementMember_doc" xml:lang="en-US"> License Agreement [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_CapitalLeaseAgreementImputedAnnualInterestRate" xlink:to="OCX_CapitalLeaseAgreementImputedAnnualInterestRate_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_CapitalLeaseAgreementImputedAnnualInterestRate_doc" xml:lang="en-US"> Refers to annual interest rate on capital lease agreement. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ExpensesAndTaxesDescription" xlink:to="OCX_ExpensesAndTaxesDescription_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ExpensesAndTaxesDescription_doc" xml:lang="en-US"> Expenses and taxes description. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PercentageOfAdiministrativeFeePaidOnOriginalCostOfEquipment" xlink:to="OCX_PercentageOfAdiministrativeFeePaidOnOriginalCostOfEquipment_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_PercentageOfAdiministrativeFeePaidOnOriginalCostOfEquipment_doc" xml:lang="en-US"> Percentage of administrative fee paid on original cost of equipment. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RoyaltyExpensesDescription" xlink:to="OCX_RoyaltyExpensesDescription_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_RoyaltyExpensesDescription_doc" xml:lang="en-US"> Royalty expenses description. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PropertySubjectToOrAvailableForFinanceLeaseGross" xlink:to="OCX_PropertySubjectToOrAvailableForFinanceLeaseGross_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_PropertySubjectToOrAvailableForFinanceLeaseGross_doc" xml:lang="en-US"> Property and equipment, gross. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_AccumulatedDepreciationForfinanceLease" xlink:to="OCX_AccumulatedDepreciationForfinanceLease_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_AccumulatedDepreciationForfinanceLease_doc" xml:lang="en-US"> Accumulated depreciation. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PropertyPlantAndEquipmentNetFinanceLease" xlink:to="OCX_PropertyPlantAndEquipmentNetFinanceLease_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_PropertyPlantAndEquipmentNetFinanceLease_doc" xml:lang="en-US"> Property and equipment, net. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LeasseeTenantImprovementAllowanceNetOfAdministrativeFee" xlink:to="OCX_LeasseeTenantImprovementAllowanceNetOfAdministrativeFee_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_LeasseeTenantImprovementAllowanceNetOfAdministrativeFee_doc" xml:lang="en-US"> Tenant Improvement Allowance, net of administrative fee. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LeasseeFinancingTenantImprovementAllowanceNetOfAdministrativeFee" xlink:to="OCX_LeasseeFinancingTenantImprovementAllowanceNetOfAdministrativeFee_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_LeasseeFinancingTenantImprovementAllowanceNetOfAdministrativeFee_doc" xml:lang="en-US"> Tenant Improvement Allowance, net of administrative fee. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SubscriptionAgreementsMember" xlink:to="OCX_SubscriptionAgreementsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_SubscriptionAgreementsMember_doc" xml:lang="en-US"> Subscription Agreements [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_MergerAgreementsMember" xlink:to="OCX_MergerAgreementsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_MergerAgreementsMember_doc" xml:lang="en-US"> Merger Agreements [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_BusinessCombinationNetCashHoldback" xlink:to="OCX_BusinessCombinationNetCashHoldback_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_BusinessCombinationNetCashHoldback_doc" xml:lang="en-US"> Net cash holdback. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_StockHoldbackShareValue" xlink:to="OCX_StockHoldbackShareValue_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_StockHoldbackShareValue_doc" xml:lang="en-US"> Stock holdback. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PaymentsOfMilestone" xlink:to="OCX_PaymentsOfMilestone_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_PaymentsOfMilestone_doc" xml:lang="en-US"> Payments of milestone. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ATMAgreementsMember" xlink:to="OCX_ATMAgreementsMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_ATMAgreementsMember_doc" xml:lang="en-US"> ATM Agreements [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_StockOptionExercisable" xlink:to="OCX_StockOptionExercisable_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_StockOptionExercisable_doc" xml:lang="en-US"> Stock options exercisable. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_LeaseContractTypeAxis" xlink:to="OCX_LeaseContractTypeAxis_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_LeaseContractTypeAxis_doc" xml:lang="en-US"> Lease Contract Type [Axis] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_OperatingLeaseMember" xlink:to="OCX_OperatingLeaseMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_OperatingLeaseMember_doc" xml:lang="en-US"> Operating Lease [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FinancingLeaseMember" xlink:to="OCX_FinancingLeaseMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_FinancingLeaseMember_doc" xml:lang="en-US"> Financing Lease [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_MinorityShareholdersMember" xlink:to="OCX_MinorityShareholdersMember_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_MinorityShareholdersMember_doc" xml:lang="en-US"> Minority Shareholders [Member] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_SharesAvailableForGrantOutstanding" xlink:to="OCX_SharesAvailableForGrantOutstanding_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_SharesAvailableForGrantOutstanding_doc" xml:lang="en-US"> Shares available for grant outstanding. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_DeferredTaxAssetsEquityMethodInvestment" xlink:to="OCX_DeferredTaxAssetsEquityMethodInvestment_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_DeferredTaxAssetsEquityMethodInvestment_doc" xml:lang="en-US"> Equity method investment. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_Seenote10foradditionaldisclosures" xlink:to="OCX_Seenote10foradditionaldisclosures_doc" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="OCX_Seenote10foradditionaldisclosures_doc" xml:lang="en-US"> Additional disclosures. </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Liabilities_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Liabilities_2_lbl" xml:lang="en-US"> Liabilities </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpenses" xlink:to="us-gaap_OperatingExpenses_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingExpenses_2_lbl" xml:lang="en-US"> Operating Expenses </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingIncomeLoss_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingIncomeLoss_2_lbl" xml:lang="en-US"> Operating Income (Loss) </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="us-gaap_NonoperatingIncomeExpense_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NonoperatingIncomeExpense_2_lbl" xml:lang="en-US"> Nonoperating Income (Expense) </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComprehensiveIncomeNetOfTax" xlink:to="us-gaap_ComprehensiveIncomeNetOfTax_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_2_lbl" xml:lang="en-US"> Comprehensive Income (Loss), Net of Tax, Attributable to Parent </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesOutstanding" xlink:to="us-gaap_SharesOutstanding_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharesOutstanding_3_lbl" xml:lang="en-US"> Shares, Outstanding </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendIncomeOperating" xlink:to="us-gaap_DividendIncomeOperating_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DividendIncomeOperating_2_lbl" xml:lang="en-US"> Dividend Income, Operating </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInDueToRelatedParties" xlink:to="us-gaap_IncreaseDecreaseInDueToRelatedParties_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInDueToRelatedParties_2_lbl" xml:lang="en-US"> Increase (Decrease) in Due to Related Parties </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:to="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_2_lbl" xml:lang="en-US"> Increase (Decrease) in Prepaid Expense and Other Assets </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_2_lbl" xml:lang="en-US"> Net Cash Provided by (Used in) Operating Activities </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireEquityMethodInvestments" xlink:to="us-gaap_PaymentsToAcquireEquityMethodInvestments_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireEquityMethodInvestments_2_lbl" xml:lang="en-US"> Payments to Acquire Equity Method Investments </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_2_lbl" xml:lang="en-US"> Payments to Acquire Property, Plant, and Equipment </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PaymentsToSecurityDepositAndOther" xlink:to="OCX_PaymentsToSecurityDepositAndOther_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_PaymentsToSecurityDepositAndOther_3_lbl" xml:lang="en-US"> PaymentsToSecurityDepositAndOther </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_2_lbl" xml:lang="en-US"> Net Cash Provided by (Used in) Investing Activities </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfStockIssuanceCosts" xlink:to="us-gaap_PaymentsOfStockIssuanceCosts_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts_2_lbl" xml:lang="en-US"> Payments of Stock Issuance Costs </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_FinancingCostsToIssueCommonSharesAndWarrants" xlink:to="OCX_FinancingCostsToIssueCommonSharesAndWarrants_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_FinancingCostsToIssueCommonSharesAndWarrants_3_lbl" xml:lang="en-US"> FinancingCostsToIssueCommonSharesAndWarrants </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_RepaymentsOfPrincipalAndBankFeesFromRefinancingOfBankLoan" xlink:to="OCX_RepaymentsOfPrincipalAndBankFeesFromRefinancingOfBankLoan_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_RepaymentsOfPrincipalAndBankFeesFromRefinancingOfBankLoan_3_lbl" xml:lang="en-US"> RepaymentsOfPrincipalAndBankFeesFromRefinancingOfBankLoan </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfDebt" xlink:to="us-gaap_RepaymentsOfDebt_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RepaymentsOfDebt_2_lbl" xml:lang="en-US"> Repayments of Debt </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_2_lbl" xml:lang="en-US"> Net Cash Provided by (Used in) Financing Activities </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_2_lbl" xml:lang="en-US"> Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxPolicyTextBlock" xlink:to="us-gaap_IncomeTaxPolicyTextBlock_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_2_lbl" xml:lang="en-US"> Income Tax, Policy [Policy Text Block] </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssetsCurrent" xlink:to="us-gaap_OtherAssetsCurrent_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherAssetsCurrent_2_lbl" xml:lang="en-US"> Other Assets, Current </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssetsNoncurrent" xlink:to="us-gaap_OtherAssetsNoncurrent_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherAssetsNoncurrent_2_lbl" xml:lang="en-US"> Other Assets, Noncurrent </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:to="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_2_lbl" xml:lang="en-US"> Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentNet" xlink:to="us-gaap_PropertyPlantAndEquipmentNet_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_2_lbl" xml:lang="en-US"> Property, Plant and Equipment, Net </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_UseFees" xlink:to="OCX_UseFees_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_UseFees_3_lbl" xml:lang="en-US"> UseFees </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentDescriptionOfPrincipalActivities" xlink:to="us-gaap_EquityMethodInvestmentDescriptionOfPrincipalActivities_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityMethodInvestmentDescriptionOfPrincipalActivities_2_lbl" xml:lang="en-US"> Equity Method Investment, Description of Principal Activities </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_PaymentsOfPrincipalAndInterest" xlink:to="OCX_PaymentsOfPrincipalAndInterest_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_PaymentsOfPrincipalAndInterest_3_lbl" xml:lang="en-US"> PaymentsOfPrincipalAndInterest </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentCarryingAmount" xlink:to="us-gaap_DebtInstrumentCarryingAmount_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentCarryingAmount_2_lbl" xml:lang="en-US"> Long-term Debt, Gross </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansPayable" xlink:to="us-gaap_LoansPayable_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LoansPayable_2_lbl" xml:lang="en-US"> Loans Payable </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_2_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_3_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableGrantsInPeriodGross" xlink:to="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableGrantsInPeriodGross_3_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="OCX_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableGrantsInPeriodGross_3_lbl" xml:lang="en-US"> Share Based Compensation Arrangement By Share Based Payment Award Options Available Grants In Period Gross </link:label>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_2_lbl" xlink:type="arc"/>
<link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_2_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period </link:label>
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6 Subsequent Filings that Reference this Filing

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

 4/16/24  Oncocyte Corp.                    10-K       12/31/23   87:30M                                    M2 Compliance LLC/FA
 4/12/23  Oncocyte Corp.                    10-K       12/31/22   94:11M                                    M2 Compliance LLC/FA
 5/02/22  Oncocyte Corp.                    10-K/A     12/31/21   12:649K                                   M2 Compliance LLC/FA
 3/11/22  Oncocyte Corp.                    10-K       12/31/21   90:10M                                    M2 Compliance LLC/FA
 4/30/21  OncoCyte Corp.                    10-K/A     12/31/20    2:488K                                   M2 Compliance LLC/FA
 3/19/21  OncoCyte Corp.                    10-K       12/31/20   93:7.4M                                   M2 Compliance LLC/FA
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