<SEC-DOCUMENT>0001193125-20-033331-index.html : 20200212
<SEC-HEADER>0001193125-20-033331.hdr.sgml : 20200212
<ACCEPTANCE-DATETIME>20200212164533
ACCESSION NUMBER:		0001193125-20-033331
CONFORMED SUBMISSION TYPE:	SC 13G
PUBLIC DOCUMENT COUNT:		4
FILED AS OF DATE:		20200212
DATE AS OF CHANGE:		20200212
GROUP MEMBERS:		AMIR NASHAT
GROUP MEMBERS:		BRIAN CHEE
GROUP MEMBERS:		BRYCE YOUNGREN
GROUP MEMBERS:		DAVID BARRETT
GROUP MEMBERS:		JONATHAN A. FLINT
GROUP MEMBERS:		POLARIS VENTURE MANAGEMENT CO VI, L.L.C.
GROUP MEMBERS:		POLARIS VENTURE PARTNERS FOUNDERS' FUND VI, L.P.
GROUP MEMBERS:		POLARIS VENTURE PARTNERS VI (AIV), L.P.
GROUP MEMBERS:		PVP VI (AIV) FEEDER CORP. HOLDING PARTNERSHIP, L.P.
GROUP MEMBERS:		TERRANCE G. MCGUIRE

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Alector, Inc.
		CENTRAL INDEX KEY:			0001653087
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				462702363
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-90858
		FILM NUMBER:		20604841

	BUSINESS ADDRESS:	
		STREET 1:		151 OYSTER POINT BLVD., SUITE 300
		CITY:			SOUTH SAN FRANCISCO
		STATE:			CA
		ZIP:			94080
		BUSINESS PHONE:		415-231-5660

	MAIL ADDRESS:	
		STREET 1:		151 OYSTER POINT BLVD., SUITE 300
		CITY:			SOUTH SAN FRANCISCO
		STATE:			CA
		ZIP:			94080

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Alector LLC
		DATE OF NAME CHANGE:	20150915

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Polaris Venture Partners VI, L.P.
		CENTRAL INDEX KEY:			0001493463
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G

	BUSINESS ADDRESS:	
		STREET 1:		ONE MARINA PARK DRIVE, 10TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02210
		BUSINESS PHONE:		781-290-0770

	MAIL ADDRESS:	
		STREET 1:		ONE MARINA PARK DRIVE, 10TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02210
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G
<SEQUENCE>1
<FILENAME>d884599dsc13g.htm
<DESCRIPTION>SC 13G
<TEXT>
Document 1 - file: d884599dsc13g.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.A
<SEQUENCE>2
<FILENAME>d884599dex99a.htm
<DESCRIPTION>EX-99.A
<TEXT>
Document 2 - file: d884599dex99a.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.B
<SEQUENCE>3
<FILENAME>d884599dex99b.htm
<DESCRIPTION>EX-99.B
<TEXT>
Document 3 - file: d884599dex99b.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.C
<SEQUENCE>4
<FILENAME>d884599dex99c.htm
<DESCRIPTION>EX-99.C
<TEXT>
Document 4 - file: d884599dex99c.htm

</DOCUMENT>
</SEC-DOCUMENT>