<SEC-DOCUMENT>0001209191-21-056096.txt : 20210915
<SEC-HEADER>0001209191-21-056096.hdr.sgml : 20210915
<ACCEPTANCE-DATETIME>20210915073011
ACCESSION NUMBER:		0001209191-21-056096
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210913
FILED AS OF DATE:		20210915
DATE AS OF CHANGE:		20210915

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Lenk Robert P
		CENTRAL INDEX KEY:			0001362635

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34375
		FILM NUMBER:		211254247

	MAIL ADDRESS:	
		STREET 1:		LUNA INNOVATIONS INCORPORATED
		STREET 2:		2851 COMMERCE STREET
		CITY:			BLACKSBURG
		STATE:			VA
		ZIP:			24060

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>2021-09-13</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001362635</rptOwnerCik>
            <rptOwnerName>Lenk Robert P</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>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-09-13</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>7000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.8587</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $1.8499 to $1.859 per share. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Andrew Sims, as attorney-in-fact</signatureName>
        <signatureDate>2021-09-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
