<SEC-DOCUMENT>0001209191-20-021042.txt : 20200324
<SEC-HEADER>0001209191-20-021042.hdr.sgml : 20200324
<ACCEPTANCE-DATETIME>20200324194956
ACCESSION NUMBER:		0001209191-20-021042
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20200320
FILED AS OF DATE:		20200324
DATE AS OF CHANGE:		20200324

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			TULLIS DICKERSON CAPITAL FOCUS III, L.P.
		CENTRAL INDEX KEY:			0001144359

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39049
		FILM NUMBER:		20739651

	BUSINESS ADDRESS:	
		STREET 1:		ONE GREENWICH PLAZA
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830
		BUSINESS PHONE:		2036298700

	MAIL ADDRESS:	
		STREET 1:		ONE GREENWICH PLAZA
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830

	FORMER NAME:	
		FORMER CONFORMED NAME:	TULLIS DICKERSON CAPITAL FOCUS III LP
		DATE OF NAME CHANGE:	20010706

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Tullis Growth Fund, L.P.
		CENTRAL INDEX KEY:			0001606950
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39049
		FILM NUMBER:		20739652

	BUSINESS ADDRESS:	
		STREET 1:		11760 U.S. HIGHWAY 1, SUITE 502W
		CITY:			PALM BEACH GARDENS
		STATE:			FL
		ZIP:			33408
		BUSINESS PHONE:		(203) 629-8700

	MAIL ADDRESS:	
		STREET 1:		11760 U.S. HIGHWAY 1, SUITE 502W
		CITY:			PALM BEACH GARDENS
		STATE:			FL
		ZIP:			33408

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			TULLIS GROWTH FUND II, L.P.
		CENTRAL INDEX KEY:			0001746842
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39049
		FILM NUMBER:		20739653

	BUSINESS ADDRESS:	
		STREET 1:		11770 US HWY 1
		STREET 2:		STE 503
		CITY:			PALM BEACH GARDENS
		STATE:			FL
		ZIP:			33408
		BUSINESS PHONE:		561-200-3300

	MAIL ADDRESS:	
		STREET 1:		11770 US HWY 1
		STREET 2:		STE 503
		CITY:			PALM BEACH GARDENS
		STATE:			FL
		ZIP:			33408

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			TULLIS DICKERSON PARTNERS III, L.L.C.
		CENTRAL INDEX KEY:			0001144364

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39049
		FILM NUMBER:		20739654

	BUSINESS ADDRESS:	
		STREET 1:		ONE GREENWICK PLAZA
		CITY:			GREENWICK
		STATE:			CT
		ZIP:			06830
		BUSINESS PHONE:		2036298700

	MAIL ADDRESS:	
		STREET 1:		ONE GREENWICK PLAZA
		CITY:			GREENWICK
		STATE:			CT
		ZIP:			06830

	FORMER NAME:	
		FORMER CONFORMED NAME:	TULLIS DICKERSON PARTNERS III LLC
		DATE OF NAME CHANGE:	20010706

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			EXAGEN INC.
		CENTRAL INDEX KEY:			0001274737
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-MEDICAL LABORATORIES [8071]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1261 LIBERTY WAY
		CITY:			VISTA
		STATE:			CA
		ZIP:			92081
		BUSINESS PHONE:		(760) 560-1501

	MAIL ADDRESS:	
		STREET 1:		1261 LIBERTY WAY
		CITY:			VISTA
		STATE:			CA
		ZIP:			92081

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	EXAGEN DIAGNOSTICS INC
		DATE OF NAME CHANGE:	20031230
</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>2020-03-20</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001274737</issuerCik>
        <issuerName>EXAGEN INC.</issuerName>
        <issuerTradingSymbol>XGN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001144359</rptOwnerCik>
            <rptOwnerName>TULLIS DICKERSON CAPITAL FOCUS III, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11770 US HIGHWAY ONE, SUITE 503</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PALM BEACH GARDENS</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33408</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001606950</rptOwnerCik>
            <rptOwnerName>Tullis Growth Fund, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11770 US HIGHWAY ONE, SUITE 503</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PALM BEACH GARDENS</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33408</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001746842</rptOwnerCik>
            <rptOwnerName>TULLIS GROWTH FUND II, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11770 US HIGHWAY ONE, SUITE 503</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PALM BEACH GARDENS</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33408</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001144364</rptOwnerCik>
            <rptOwnerName>TULLIS DICKERSON PARTNERS III, L.L.C.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11770 US HIGHWAY ONE, SUITE 503</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PALM BEACH GARDENS</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33408</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-03-20</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>164420</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1625165</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Tullis and Tullis Growth, respectively, (as each is defined in Footnote (2) below) distributed in the aggregate 164,420 shares of Common Stock of Exagen Inc. to their respective non-affiliate limited partners on a pro rata basis, for no consideration.</footnote>
        <footnote id="F2">The shares reported on this form are held of record by Tullis-Dickerson Capital Focus III, L.P. (&quot;Tullis&quot;), Tullis Growth Fund, L.P. (&quot;Tullis Growth&quot;) and Tullis Growth Fund II, L.P. (&quot;Tullis Growth II&quot;). Tullis-Dickerson Partners III, LLC (&quot;Tullis Partners&quot;) is the general partner of Tullis and may be deemed to beneficially own the securities held by Tullis. Tullis Growth Partners, LLC and Tullis Growth Partners II, LLC are the general partners of Tullis Growth and Tullis Growth II, respectively, and may be deemed to beneficially own the securities held by Tullis Growth and Tullis Growth II. James L.L. Tullis is a Principal of each of the foregoing entities and may be deemed to possess voting and investment control over, and may be deemed to have an indirect beneficial ownership with respect to, the shares held by Tullis, Tullis Growth and Tullis Growth II.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Tullis-Dickerson Capital Focus III, L.P., By: Tullis-Dickerson Partners, L.L.C., its general partner, /s/ James L. L. Tullis, Name: James L.L. Tullis, Title: Manager</signatureName>
        <signatureDate>2020-03-24</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Tullis Growth Fund, L.P., By: Tullis-Growth Partners, L.L.C., its general partner, /s/ James L. L. Tullis, Name: James L.L. Tullis, Title: Manager</signatureName>
        <signatureDate>2020-03-24</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Tullis Growth Fund II, L.P., By: Tullis-Growth Partners II, L.L.C., its general partner, /s/ James L. L. Tullis, Name: James L.L. Tullis, Title: Manager</signatureName>
        <signatureDate>2020-03-24</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Tullis-Dickerson Partners III, L.L.C., /s/ James L. L. Tullis, Name: James L.L. Tullis, Title: Manager</signatureName>
        <signatureDate>2020-03-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
