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Illumina, Inc. – ‘10-K’ for 1/1/17 – ‘EX-101.DEF’

On:  Monday, 2/13/17, at 6:01pm ET   ·   As of:  2/14/17   ·   For:  1/1/17   ·   Accession #:  1110803-17-14   ·   File #:  1-35406

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

 2/14/17  Illumina, Inc.                    10-K        1/01/17  119:13M

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   1.14M 
 2: EX-10.28    Material Contract                                   HTML     59K 
 3: EX-10.29    Material Contract                                   HTML     97K 
 4: EX-10.30    Material Contract                                   HTML    392K 
 5: EX-10.31    Material Contract                                   HTML     79K 
 6: EX-21.1     Subsidiaries List                                   HTML     46K 
 7: EX-23.1     Consent of Experts or Counsel                       HTML     39K 
 8: EX-31.1     Certification -- §302 - SOA'02                      HTML     46K 
 9: EX-31.2     Certification -- §302 - SOA'02                      HTML     45K 
10: EX-32.1     Certification -- §906 - SOA'02                      HTML     39K 
11: EX-32.2     Certification -- §906 - SOA'02                      HTML     39K 
18: R1          Document and Entity Information Document            HTML     63K 
19: R2          Consolidated Balance Sheets                         HTML    128K 
20: R3          Consolidated Balance Sheets (Parenthetical)         HTML     52K 
21: R4          Consolidated Statements of Income                   HTML    124K 
22: R5          Consolidated Statements of Comprehensive Income     HTML     52K 
23: R6          Consolidated Statements of Stockholders' Equity     HTML    119K 
24: R7          Consolidated Statements of Cash Flows               HTML    157K 
25: R8          Organization and Summary of Significant Accounting  HTML    152K 
                Policies                                                         
26: R9          Balance Sheet Account Details                       HTML    168K 
27: R10         Intangible Assets                                   HTML     79K 
28: R11         Fair Value Measurements                             HTML    123K 
29: R12         Debt                                                HTML     80K 
30: R13         Commitments                                         HTML     94K 
31: R14         Share-based Compensation Expense                    HTML     73K 
32: R15         Stockholders' Equity                                HTML    161K 
33: R16         Legal Proceedings                                   HTML     58K 
34: R17         Income Taxes                                        HTML    158K 
35: R18         Employee Benefit Plans                              HTML     45K 
36: R19         Segment Information, Geographic Data, and           HTML    137K 
                Significant Customers                                            
37: R20         Quarterly Financial Information (Unaudited)         HTML     89K 
38: R21         Schedule Ii - Valuation and Qualifying Accounts     HTML     59K 
                and Reserves                                                     
39: R22         Organization and Summary of Significant Accounting  HTML    214K 
                Policies (Policies)                                              
40: R23         Organization and Summary of Significant Accounting  HTML    104K 
                Policies (Tables)                                                
41: R24         Balance Sheet Account Details (Tables)              HTML    158K 
42: R25         Intangible Assets (Tables)                          HTML     79K 
43: R26         Fair Value Measurements (Tables)                    HTML    118K 
44: R27         Debt (Tables)                                       HTML     58K 
45: R28         Commitments (Tables)                                HTML     95K 
46: R29         Share-based Compensation Expense (Tables)           HTML     73K 
47: R30         Stockholders' Equity (Tables)                       HTML    235K 
48: R31         Income Taxes (Tables)                               HTML    151K 
49: R32         Segment Information, Geographic Data, and           HTML    129K 
                Significant Customers (Tables)                                   
50: R33         Quarterly Financial Information (Unaudited)         HTML     87K 
                (Tables)                                                         
51: R34         Organization and Summary of Significant Accounting  HTML     44K 
                Policies - Narrative - Recent Accounting Policies                
                (Details)                                                        
52: R35         Organization and Summary of Significant Accounting  HTML     56K 
                Policies - Narrative - Concentrations of Risk                    
                (Details)                                                        
53: R36         Organization and Summary of Significant Accounting  HTML     40K 
                Policies - Narrative - Acquisitions (Details)                    
54: R37         Organization and Summary of Significant Accounting  HTML     50K 
                Policies - Summary of Estimated Useful Lives of                  
                Major Classes of Property and Equipment (Details)                
55: R38         Organization and Summary of Significant Accounting  HTML     40K 
                Policies - Narrative - Derivatives (Details)                     
56: R39         Organization and Summary of Significant Accounting  HTML     43K 
                Policies - Narrative - Warranties (Details)                      
57: R40         Organization and Summary of Significant Accounting  HTML     43K 
                Policies - Narrative - Revenue Recognition                       
                (Details)                                                        
58: R41         Organization and Summary of Significant Accounting  HTML     38K 
                Policies - Narrative - Share-Based Compensation                  
                (Details)                                                        
59: R42         Organization and Summary of Significant Accounting  HTML     38K 
                Policies - Narrative - Advertising Costs (Details)               
60: R43         Organization and Summary of Significant Accounting  HTML     56K 
                Policies - Summary of Calculation of Weighted                    
                Average Shares used to Calculate Basic and Diluted               
                Earnings Per Share (Details)                                     
61: R44         Organization and Summary of Significant Accounting  HTML     47K 
                Policies - Summary of Components of Accumulated                  
                Other Comprehensive Income (Details)                             
62: R45         Balance Sheet Account Details - Summary of          HTML     55K 
                Short-term Investments (Details)                                 
63: R46         Balance Sheet Account Details - Summary of          HTML     43K 
                Contractual Maturities of Available-for-sale Debt                
                Securities (Details)                                             
64: R47         Balance Sheet Account Details - Narrative -         HTML     61K 
                Strategic Investments (Details)                                  
65: R48         Balance Sheet Account Details - Summary of          HTML     49K 
                Accounts Receivable (Details)                                    
66: R49         Balance Sheet Account Details - Summary of          HTML     46K 
                Inventory (Details)                                              
67: R50         Balance Sheet Account Details - Summary of          HTML     58K 
                Property and Equipment (Details)                                 
68: R51         Balance Sheet Account Details - Narrative -         HTML     46K 
                Property and Equipment (Details)                                 
69: R52         Balance Sheet Account Details - Summary of Changes  HTML     41K 
                in Goodwill (Details)                                            
70: R53         Balance Sheet Account Details - Summary of Accrued  HTML     56K 
                Liabilities (Details)                                            
71: R54         Balance Sheet Account Details - Narrative -         HTML     41K 
                Build-to-Suit Lease Liability (Details)                          
72: R55         Balance Sheet Account Details - Narrative -         HTML     83K 
                Investment in Consolidated Variable Interest                     
                Entities (Details)                                               
73: R56         Balance Sheet Account Details - Summary of          HTML     48K 
                Activity of Redeemable Noncontrolling Interests                  
                (Details)                                                        
74: R57         Intangible Assets - Summary of Identifiable         HTML     57K 
                Intangible Assets (Details)                                      
75: R58         Intangible Assets - Narrative (Details)             HTML     48K 
76: R59         Intangible Assets - Summary of the Estimated        HTML     52K 
                Annual Amortization of Intangible Assets (Details)               
77: R60         Fair Value Measurements - Summary of Fair Value     HTML     81K 
                Hierarchy for Assets and Liabilities Measured at                 
                Fair Value on a Recurring Basis (Details)                        
78: R61         Fair Value Measurements - Narrative (Details)       HTML     48K 
79: R62         Fair Value Measurements - Summary of Changes in     HTML     53K 
                Estimated Fair Value of Contingent Consideration                 
                Liabilities (Details)                                            
80: R63         Debt - Narrative (Details)                          HTML    116K 
81: R64         Debt - Summary of Conversion of 2016 Notes          HTML     52K 
                (Details)                                                        
82: R65         Debt - Summary of Information about Equity and      HTML     59K 
                Liability Components of Convertible Senior Notes                 
                Outstanding (Details)                                            
83: R66         Debt - Other Narrative (Details)                    HTML     46K 
84: R67         Commitments - Narrative (Details)                   HTML     38K 
85: R68         Commitments - Summary of Annual Future Minimum      HTML    102K 
                Payments under Leases (Details)                                  
86: R69         Commitments - Summary of Changes in the Facility    HTML     48K 
                Exit Obligation (Details)                                        
87: R70         Commitments - Summary of Annual Future Minimum      HTML     48K 
                Royalty Payments under Licensing Agreements                      
                (Details)                                                        
88: R71         Commitments - Summary of Changes in Reserve for     HTML     44K 
                Product Warranties (Details)                                     
89: R72         Share-based Compensation Expense - Summary of       HTML     53K 
                Share-based Compensation Expense for all Stock                   
                Awards (Details)                                                 
90: R73         Share-based Compensation Expense - Summary of       HTML     60K 
                Assumptions used to Estimate the Weighted-Average                
                Fair Value Per Share for Stock Purchase under the                
                Employee Stock Purchase Plan (Details)                           
91: R74         Share-based Compensation Expense - Narrative        HTML     40K 
                (Details)                                                        
92: R75         Stockholders' Equity - Summary of Restricted Stock  HTML     77K 
                Activity and Related Information (Details)                       
93: R76         Stockholders' Equity - Summary of Pre-tax           HTML     48K 
                Intrinsic Values and Total Fair Value of Vested                  
                Restricted Stock (Details)                                       
94: R77         Stockholders' Equity - Summary of Stock Option      HTML     55K 
                Activity Under all Stock Option Plans (Details)                  
95: R78         Stockholders' Equity - Narrative (Details)          HTML     40K 
96: R79         Stockholders' Equity - Narrative - Restricted       HTML     57K 
                Stock (Details)                                                  
97: R80         Stockholders' Equity - Narrative - Stock Options    HTML     77K 
                (Details)                                                        
98: R81         Stockholders' Equity - Narrative - Employee Stock   HTML     48K 
                Purchase Plan (Details)                                          
99: R82         Stockholders' Equity - Narrative - Warrants         HTML     45K 
                (Details)                                                        
100: R83         Stockholders' Equity - Narrative - Share            HTML     50K  
                Repurchases (Details)                                            
101: R84         Legal Proceedings - Narrative (Details)             HTML     84K  
102: R85         Income Taxes - Summary of Income before Income      HTML     43K  
                Taxes by Region (Details)                                        
103: R86         Income Taxes - Summary of Provision for Income      HTML     67K  
                Taxes (Details)                                                  
104: R87         Income Taxes - Summary of Reconciliation of         HTML     61K  
                Provision for Income Taxes to Amount Computed by                 
                Applying the Federal Statutory Rate (Details)                    
105: R88         Income Taxes - Narrative (Details)                  HTML     78K  
106: R89         Income Taxes - Summary of Significant Components    HTML     85K  
                of Deferred Tax Assets and Liabilities (Details)                 
107: R90         Income Taxes - Summary of the Gross Amount of       HTML     49K  
                Uncertain Tax Positions (Details)                                
108: R91         Employee Benefit Plans - Retirement Plan Narrative  HTML     38K  
                (Details)                                                        
109: R92         Employee Benefit Plans - Deferred Comp Narrative    HTML     53K  
                (Details)                                                        
110: R93         Segment Information, Geographic Data, and           HTML     66K  
                Significant Customers - Summary of Operating                     
                Performance and Assets by Segment (Details)                      
111: R94         Segment Information, Geographic Data, and           HTML     39K  
                Significant Customers - Narrative (Segments)                     
                (Details)                                                        
112: R95         Segment Information, Geographic Data, and           HTML     53K  
                Significant Customers - Summary of Revenue by                    
                Region (Details)                                                 
113: R96         Segment Information, Geographic Data, and           HTML     46K  
                Significant Customers - Narrative (Details)                      
114: R97         Segment Information, Geographic Data, and           HTML     48K  
                Significant Customers - Summary of Net Long-lived                
                Assets Consisting of Property and Equipment by                   
                Region (Details)                                                 
115: R98         Quarterly Financial Information (unaudited) -       HTML     62K  
                Summary of Quarterly Data (Details)                              
116: R99         Schedule Ii - Valuation and Qualifying Accounts     HTML     45K  
                and Reserves (Details)                                           
118: XML         IDEA XML File -- Filing Summary                      XML    219K  
117: EXCEL       IDEA Workbook of Financial Reports                  XLSX    136K  
12: EX-101.INS  XBRL Instance -- ilmn-20170101                       XML   3.57M 
14: EX-101.CAL  XBRL Calculations -- ilmn-20170101_cal               XML    381K 
15: EX-101.DEF  XBRL Definitions -- ilmn-20170101_def                XML    926K 
16: EX-101.LAB  XBRL Labels -- ilmn-20170101_lab                     XML   2.47M 
17: EX-101.PRE  XBRL Presentations -- ilmn-20170101_pre              XML   1.49M 
13: EX-101.SCH  XBRL Schema -- ilmn-20170101                         XSD    231K 
119: ZIP         XBRL Zipped Folder -- 0001110803-17-000014-xbrl      Zip    353K  


‘EX-101.DEF’   —   XBRL Definitions — ilmn-20170101_def


This Exhibit is an XBRL XML File.


                                                                                                                                                                                
<?xml version="1.0" encoding="windows-1252"?>
<!-- XBRL Document Created with Wdesk from Workiva -->
<!-- -->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<link:roleRef roleURI="http://www.illumina.com/role/BalanceSheetAccountDetails" xlink:href="ilmn-20170101.xsd#BalanceSheetAccountDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/BalanceSheetAccountDetailsNarrativeBuildToSuitLeaseLiabilityDetails" xlink:href="ilmn-20170101.xsd#BalanceSheetAccountDetailsNarrativeBuildToSuitLeaseLiabilityDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/BalanceSheetAccountDetailsNarrativeInvestmentInConsolidatedVariableInterestEntitiesDetails" xlink:href="ilmn-20170101.xsd#BalanceSheetAccountDetailsNarrativeInvestmentInConsolidatedVariableInterestEntitiesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/BalanceSheetAccountDetailsNarrativePropertyAndEquipmentDetails" xlink:href="ilmn-20170101.xsd#BalanceSheetAccountDetailsNarrativePropertyAndEquipmentDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/BalanceSheetAccountDetailsNarrativeStrategicInvestmentsDetails" xlink:href="ilmn-20170101.xsd#BalanceSheetAccountDetailsNarrativeStrategicInvestmentsDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/BalanceSheetAccountDetailsSummaryOfAccountsReceivableDetails" xlink:href="ilmn-20170101.xsd#BalanceSheetAccountDetailsSummaryOfAccountsReceivableDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/BalanceSheetAccountDetailsSummaryOfAccruedLiabilitiesDetails" xlink:href="ilmn-20170101.xsd#BalanceSheetAccountDetailsSummaryOfAccruedLiabilitiesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/BalanceSheetAccountDetailsSummaryOfActivityOfRedeemableNoncontrollingInterestsDetails" xlink:href="ilmn-20170101.xsd#BalanceSheetAccountDetailsSummaryOfActivityOfRedeemableNoncontrollingInterestsDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/BalanceSheetAccountDetailsSummaryOfChangesInGoodwillDetails" xlink:href="ilmn-20170101.xsd#BalanceSheetAccountDetailsSummaryOfChangesInGoodwillDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/BalanceSheetAccountDetailsSummaryOfContractualMaturitiesOfAvailableForSaleDebtSecuritiesDetails" xlink:href="ilmn-20170101.xsd#BalanceSheetAccountDetailsSummaryOfContractualMaturitiesOfAvailableForSaleDebtSecuritiesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/BalanceSheetAccountDetailsSummaryOfInventoryDetails" xlink:href="ilmn-20170101.xsd#BalanceSheetAccountDetailsSummaryOfInventoryDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/BalanceSheetAccountDetailsSummaryOfPropertyAndEquipmentDetails" xlink:href="ilmn-20170101.xsd#BalanceSheetAccountDetailsSummaryOfPropertyAndEquipmentDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/BalanceSheetAccountDetailsSummaryOfShortTermInvestmentsDetails" xlink:href="ilmn-20170101.xsd#BalanceSheetAccountDetailsSummaryOfShortTermInvestmentsDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/BalanceSheetAccountDetailsTables" xlink:href="ilmn-20170101.xsd#BalanceSheetAccountDetailsTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/Commitments" xlink:href="ilmn-20170101.xsd#Commitments" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/CommitmentsNarrativeDetails" xlink:href="ilmn-20170101.xsd#CommitmentsNarrativeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/CommitmentsSummaryOfAnnualFutureMinimumPaymentsUnderLeasesDetails" xlink:href="ilmn-20170101.xsd#CommitmentsSummaryOfAnnualFutureMinimumPaymentsUnderLeasesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/CommitmentsSummaryOfAnnualFutureMinimumRoyaltyPaymentsUnderLicensingAgreementsDetails" xlink:href="ilmn-20170101.xsd#CommitmentsSummaryOfAnnualFutureMinimumRoyaltyPaymentsUnderLicensingAgreementsDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/CommitmentsSummaryOfChangesInFacilityExitObligationDetails" xlink:href="ilmn-20170101.xsd#CommitmentsSummaryOfChangesInFacilityExitObligationDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/CommitmentsSummaryOfChangesInReserveForProductWarrantiesDetails" xlink:href="ilmn-20170101.xsd#CommitmentsSummaryOfChangesInReserveForProductWarrantiesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/CommitmentsTables" xlink:href="ilmn-20170101.xsd#CommitmentsTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/ConsolidatedBalanceSheets" xlink:href="ilmn-20170101.xsd#ConsolidatedBalanceSheets" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:href="ilmn-20170101.xsd#ConsolidatedBalanceSheetsParenthetical" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/ConsolidatedStatementsOfCashFlows" xlink:href="ilmn-20170101.xsd#ConsolidatedStatementsOfCashFlows" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:href="ilmn-20170101.xsd#ConsolidatedStatementsOfComprehensiveIncome" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/ConsolidatedStatementsOfIncome" xlink:href="ilmn-20170101.xsd#ConsolidatedStatementsOfIncome" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/ConsolidatedStatementsOfStockholdersEquity" xlink:href="ilmn-20170101.xsd#ConsolidatedStatementsOfStockholdersEquity" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/Debt" xlink:href="ilmn-20170101.xsd#Debt" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/DebtNarrativeDetails" xlink:href="ilmn-20170101.xsd#DebtNarrativeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/DebtOtherNarrativeDetails" xlink:href="ilmn-20170101.xsd#DebtOtherNarrativeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/DebtSummaryOfConversionOf2016NotesDetails" xlink:href="ilmn-20170101.xsd#DebtSummaryOfConversionOf2016NotesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/DebtSummaryOfInformationAboutEquityAndLiabilityComponentsOfConvertibleSeniorNotesOutstandingDetails" xlink:href="ilmn-20170101.xsd#DebtSummaryOfInformationAboutEquityAndLiabilityComponentsOfConvertibleSeniorNotesOutstandingDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/DebtTables" xlink:href="ilmn-20170101.xsd#DebtTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/DocumentAndEntityInformationDocument" xlink:href="ilmn-20170101.xsd#DocumentAndEntityInformationDocument" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/EmployeeBenefitPlans" xlink:href="ilmn-20170101.xsd#EmployeeBenefitPlans" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/EmployeeBenefitPlansDeferredCompNarrativeDetails" xlink:href="ilmn-20170101.xsd#EmployeeBenefitPlansDeferredCompNarrativeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/EmployeeBenefitPlansRetirementPlanNarrativeDetails" xlink:href="ilmn-20170101.xsd#EmployeeBenefitPlansRetirementPlanNarrativeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/FairValueMeasurements" xlink:href="ilmn-20170101.xsd#FairValueMeasurements" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/FairValueMeasurementsNarrativeDetails" xlink:href="ilmn-20170101.xsd#FairValueMeasurementsNarrativeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/FairValueMeasurementsSummaryOfChangesInEstimatedFairValueOfContingentConsiderationLiabilitiesDetails" xlink:href="ilmn-20170101.xsd#FairValueMeasurementsSummaryOfChangesInEstimatedFairValueOfContingentConsiderationLiabilitiesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/FairValueMeasurementsSummaryOfFairValueHierarchyForAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetails" xlink:href="ilmn-20170101.xsd#FairValueMeasurementsSummaryOfFairValueHierarchyForAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/FairValueMeasurementsTables" xlink:href="ilmn-20170101.xsd#FairValueMeasurementsTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/IncomeTaxes" xlink:href="ilmn-20170101.xsd#IncomeTaxes" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/IncomeTaxesNarrativeDetails" xlink:href="ilmn-20170101.xsd#IncomeTaxesNarrativeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/IncomeTaxesSummaryOfGrossAmountOfUncertainTaxPositionsDetails" xlink:href="ilmn-20170101.xsd#IncomeTaxesSummaryOfGrossAmountOfUncertainTaxPositionsDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/IncomeTaxesSummaryOfIncomeBeforeIncomeTaxesByRegionDetails" xlink:href="ilmn-20170101.xsd#IncomeTaxesSummaryOfIncomeBeforeIncomeTaxesByRegionDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/IncomeTaxesSummaryOfProvisionForIncomeTaxesDetails" xlink:href="ilmn-20170101.xsd#IncomeTaxesSummaryOfProvisionForIncomeTaxesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/IncomeTaxesSummaryOfReconciliationOfProvisionForIncomeTaxesToAmountComputedByApplyingFederalStatutoryRateDetails" xlink:href="ilmn-20170101.xsd#IncomeTaxesSummaryOfReconciliationOfProvisionForIncomeTaxesToAmountComputedByApplyingFederalStatutoryRateDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/IncomeTaxesSummaryOfSignificantComponentsOfDeferredTaxAssetsAndLiabilitiesDetails" xlink:href="ilmn-20170101.xsd#IncomeTaxesSummaryOfSignificantComponentsOfDeferredTaxAssetsAndLiabilitiesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/IncomeTaxesTables" xlink:href="ilmn-20170101.xsd#IncomeTaxesTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/IntangibleAssets" xlink:href="ilmn-20170101.xsd#IntangibleAssets" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/IntangibleAssetsNarrativeDetails" xlink:href="ilmn-20170101.xsd#IntangibleAssetsNarrativeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/IntangibleAssetsSummaryOfEstimatedAnnualAmortizationOfIntangibleAssetsDetails" xlink:href="ilmn-20170101.xsd#IntangibleAssetsSummaryOfEstimatedAnnualAmortizationOfIntangibleAssetsDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/IntangibleAssetsSummaryOfIdentifiableIntangibleAssetsDetails" xlink:href="ilmn-20170101.xsd#IntangibleAssetsSummaryOfIdentifiableIntangibleAssetsDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/IntangibleAssetsTables" xlink:href="ilmn-20170101.xsd#IntangibleAssetsTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/LegalProceedings" xlink:href="ilmn-20170101.xsd#LegalProceedings" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/LegalProceedingsNarrativeDetails" xlink:href="ilmn-20170101.xsd#LegalProceedingsNarrativeDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.illumina.com/role/OrganizationAndSummaryOfSignificantAccountingPolicies" xlink:href="ilmn-20170101.xsd#OrganizationAndSummaryOfSignificantAccountingPolicies" xlink:type="simple"/>
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4 Subsequent Filings that Reference this Filing

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

 2/16/24  Illumina, Inc.                    10-K       12/31/23  111:18M
 2/17/23  Illumina, Inc.                    10-K        1/01/23  108:17M
 2/18/22  Illumina, Inc.                    10-K        1/02/22  108:15M
 2/17/21  Illumina, Inc.                    10-K        1/03/21  102:13M
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