<SEC-DOCUMENT>0000899243-21-046120.txt : 20211124
<SEC-HEADER>0000899243-21-046120.hdr.sgml : 20211124
<ACCEPTANCE-DATETIME>20211124210925
ACCESSION NUMBER:		0000899243-21-046120
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20211111
FILED AS OF DATE:		20211124
DATE AS OF CHANGE:		20211124

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LaFrance Norman D.
		CENTRAL INDEX KEY:			0001397768

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34375
		FILM NUMBER:		211448928

	MAIL ADDRESS:	
		STREET 1:		MOLECULAR INSIGHT PHARMCEUTICALS, INC.
		STREET 2:		160 SECOND STREET
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02142

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PLUS THERAPEUTICS, INC.
		CENTRAL INDEX KEY:			0001095981
		STANDARD INDUSTRIAL CLASSIFICATION:	SURGICAL & MEDICAL INSTRUMENTS & APPARATUS [3841]
		IRS NUMBER:				330827593
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		4200 MARATHON BLVD.
		STREET 2:		SUITE 200
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78756
		BUSINESS PHONE:		737.255.7194

	MAIL ADDRESS:	
		STREET 1:		4200 MARATHON BLVD.
		STREET 2:		SUITE 200
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78756

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CYTORI THERAPEUTICS, INC.
		DATE OF NAME CHANGE:	20050712

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MACROPORE INC
		DATE OF NAME CHANGE:	20010320
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-11-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001095981</issuerCik>
        <issuerName>PLUS THERAPEUTICS, INC.</issuerName>
        <issuerTradingSymbol>PSTV</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001397768</rptOwnerCik>
            <rptOwnerName>LaFrance Norman D.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PLUS THERAPEUTICS INC.</rptOwnerStreet1>
            <rptOwnerStreet2>4200 MARATHON BOULEVARD, SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>AUSTIN</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78756</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CHIEF MEDICAL OFFICER</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (right to buy shares of common stock)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>120000.00</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-11-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>120000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2031-11-11</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>120000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>120000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">25% of the options will vest on November 11, 2022 with the remaining options vesting over the subsequent three years in equal monthly installments.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Andrew Sims, as attorney-in-fact</signatureName>
        <signatureDate>2021-11-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
