<SEC-DOCUMENT>0001070081-17-000045.txt : 20170106
<SEC-HEADER>0001070081-17-000045.hdr.sgml : 20170106
<ACCEPTANCE-DATETIME>20170106180136
ACCESSION NUMBER:		0001070081-17-000045
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20170105
FILED AS OF DATE:		20170106
DATE AS OF CHANGE:		20170106

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PTC THERAPEUTICS, INC.
		CENTRAL INDEX KEY:			0001070081
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				043416587
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		100 CORPORATE COURT
		CITY:			SOUTH PLAINFIELD
		STATE:			NJ
		ZIP:			07080-2449
		BUSINESS PHONE:		9082227000

	MAIL ADDRESS:	
		STREET 1:		100 CORPORATE COURT
		CITY:			SOUTH PLAINFIELD
		STATE:			NJ
		ZIP:			07080-2449

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	PTC THERAPEUTICS INC
		DATE OF NAME CHANGE:	19980909

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Almstead Neil Gregory
		CENTRAL INDEX KEY:			0001578850

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35969
		FILM NUMBER:		17515361

	MAIL ADDRESS:	
		STREET 1:		C/O PTC THERAPEUTICS, INC.
		STREET 2:		100 CORPORATE COURT
		CITY:			SOUTH PLAINFIELD
		STATE:			NJ
		ZIP:			07080
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_148374368411152.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-01-05</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001070081</issuerCik>
        <issuerName>PTC THERAPEUTICS, INC.</issuerName>
        <issuerTradingSymbol>PTCT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001578850</rptOwnerCik>
            <rptOwnerName>Almstead Neil Gregory</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PTC THERAPEUTICS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>100 CORPORATE COURT</rptOwnerStreet2>
            <rptOwnerCity>SOUTH PLAINFIELD</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07080</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP Research Pharma Ops &amp; Tech</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-01-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>78</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>11.82</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2687</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By spouse</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares automatically sold pursuant to an irrevocable sell to cover election to satisfy tax withholding obligations in connection with the vesting of 187 RSUs from a January 4, 2016 grant of 750 shares.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Colleen Diver Johnson, attorney-in-fact</signatureName>
        <signatureDate>2017-01-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
