<SEC-DOCUMENT>0001209191-21-049151.txt : 20210802
<SEC-HEADER>0001209191-21-049151.hdr.sgml : 20210802
<ACCEPTANCE-DATETIME>20210802212358
ACCESSION NUMBER:		0001209191-21-049151
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210729
FILED AS OF DATE:		20210802
DATE AS OF CHANGE:		20210802

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Brandt Peter C.
		CENTRAL INDEX KEY:			0001434099

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39692
		FILM NUMBER:		211137619

	MAIL ADDRESS:	
		STREET 1:		NOVEN PHARMACEUTICALS, INC.
		STREET 2:		11960 SW 144TH STREET
		CITY:			MIAMI
		STATE:			FL
		ZIP:			33186

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			IN8BIO, INC.
		CENTRAL INDEX KEY:			0001740279
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				825462585
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		79 MADISON AVENUE, 2ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10016
		BUSINESS PHONE:		(646) 600-6438

	MAIL ADDRESS:	
		STREET 1:		79 MADISON AVENUE, 2ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10016

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Incysus Therapeutics, Inc.
		DATE OF NAME CHANGE:	20180510
</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>2021-07-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001740279</issuerCik>
        <issuerName>IN8BIO, INC.</issuerName>
        <issuerTradingSymbol>INAB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001434099</rptOwnerCik>
            <rptOwnerName>Brandt Peter C.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O IN8BIO, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>79 MADISON AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10016</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>10.00</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-07-29</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>10500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2031-07-29</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">One twelfth (1/12th) of the shares subject to the option shall vest in equal monthly installments commencing on August 29, 2021 and will be fully vested on the date of the next annual meeting of the Issuer's stockholders, subject to the Reporting Person continuing to provide service through each such date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jason Minio, Attorney-in-Fact</signatureName>
        <signatureDate>2021-08-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
