<SEC-DOCUMENT>0000939767-18-000062.txt : 20180430
<SEC-HEADER>0000939767-18-000062.hdr.sgml : 20180430
<ACCEPTANCE-DATETIME>20180430202337
ACCESSION NUMBER:		0000939767-18-000062
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180427
FILED AS OF DATE:		20180430
DATE AS OF CHANGE:		20180430

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Hessekiel Jeffrey
		CENTRAL INDEX KEY:			0001599803

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-30235
		FILM NUMBER:		18792644

	MAIL ADDRESS:	
		STREET 1:		210 EAST GRAND AVE.
		CITY:			SOUTH SAN FRANCISCO
		STATE:			CA
		ZIP:			94080

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			EXELIXIS, INC.
		CENTRAL INDEX KEY:			0000939767
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMMERCIAL PHYSICAL & BIOLOGICAL RESEARCH [8731]
		IRS NUMBER:				043257395
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0102

	BUSINESS ADDRESS:	
		STREET 1:		210 E. GRAND AVE
		CITY:			SOUTH SAN FRANCISCO
		STATE:			CA
		ZIP:			94080
		BUSINESS PHONE:		6508377000

	MAIL ADDRESS:	
		STREET 1:		210 E. GRAND AVE
		CITY:			SOUTH SAN FRANCISCO
		STATE:			CA
		ZIP:			94080

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	EXELIXIS INC
		DATE OF NAME CHANGE:	20000207

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	EXELIXIS PHARMACEUTICALS INC
		DATE OF NAME CHANGE:	20000106
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_152513420417985.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-04-27</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000939767</issuerCik>
        <issuerName>EXELIXIS, INC.</issuerName>
        <issuerTradingSymbol>EXEL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001599803</rptOwnerCik>
            <rptOwnerName>Hessekiel Jeffrey</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O EXELIXIS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>210 E. GRAND AVE.</rptOwnerStreet2>
            <rptOwnerCity>SOUTH SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94080</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP and General Counsel</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-04-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>25000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.70</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>339450</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>617</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401(k)</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.7</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-04-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>25000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2015-07-20</value>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2021-09-18</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>25000.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>120000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Includes 62,187 shares of Exelixis, Inc. common stock that will be issued to the Reporting Person upon vesting of restricted stock units and 1,008 shares of common stock acquired on April 30, 2018, pursuant to the Exelixis, Inc. 2000 Employee Stock Purchase Plan.</footnote>
        <footnote id="F2">Represents shares of Exelixis, Inc. common stock under the Exelixis, Inc. 401(k) Plan, pursuant to a plan statement dated as of April 23, 2018.</footnote>
        <footnote id="F3">The option, representing the right to purchase a total of 400,000 shares of Exelixis, Inc. common stock, became fully exercisable on April 28, 2016.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jennifer Drimmer Rokovich, Attorney in Fact</signatureName>
        <signatureDate>2018-04-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
