Flagship Pioneering Form 3 Sigilon Therapeutics / NOUBAR AFEYAN ownership change

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person^*

Flagship Ventures Fund V General Partner LLC

(Last) (First) (Middle)

C/O FLAGSHIP PIONEERING INC.

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
12/03/2020

3. Issuer Name and Ticker or Trading Symbol
Sigilon Therapeutics, Inc. [ SGTX ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

Director	X	10% Owner
Officer (give title below)		Other (specify below)

5. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series A Convertible Preferred Stock	(1)	(1)	Common Stock	4,444,444	(1)	I	See Footnote(2)
Series A-1 Convertible Preferred Stock	(1)	(1)	Common Stock	4,074,074	(1)	I	See Footnote(2)
Series B Convertible Preferred Stock	(1)	(1)	Common Stock	370,370	(1)	I	See Footnote(2)
Series B Convertible Preferred Stock	(1)	(1)	Common Stock	1,481,481	(1)	I	See Footnote(3)

1. Name and Address of Reporting Person^*

Flagship Ventures Fund V General Partner LLC

(Last) (First) (Middle)

C/O FLAGSHIP PIONEERING INC.

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship Ventures Fund V, L.P.

(Last) (First) (Middle)

C/O FLAGSHIP PIONEERING INC.

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship Pioneering Special Opportunities Fund II, L.P.

(Last) (First) (Middle)

C/O FLAGSHIP PIONEERING INC.

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship Pioneering Special Opportunities Fund II General Partner LLC

(Last) (First) (Middle)

C/O FLAGSHIP PIONEERING INC.

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship Pioneering Inc.

(Last) (First) (Middle)

C/O FLAGSHIP PIONEERING INC.

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

AFEYAN NOUBAR

(Last) (First) (Middle)

C/O FLAGSHIP PIONEERING INC.

55 CAMBRIDGE PARKWAY, SUITE 800E

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

Explanation of Responses:

1. The Series A Convertible Preferred Stock, Series A-1 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") is convertible into the number of shares of the Registrant's common stock shown in column 3 and has no expiration date. The Preferred Stock will automatically convert into common stock upon the closing of the Registrant's initial public offering.

2. Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Fund V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan Ph.D. serves as the sole manager of Fund V GP. Each of Fund V GP and Noubar B. Afeyan Ph.D. disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

3. Shares held by Flagship Pioneering Special Opportunities Fund II, L.P. ("Flagship Opportunities Fund II"). Flagship Pioneering Special Opportunities Fund II General Partner LLC ("Opportunities Fund II GP") is the general partner of Flagship Opportunities Fund II. Flagship Pioneering, Inc. ("Flagship Pioneering") is the manager of Opportunities Fund II GP. Noubar B. Afeyan, Ph.D. is sole director of Flagship Pioneering. Each of Noubar B. Afeyan Ph.D., Flagship Pioneering, and Opportunities Fund II GP disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

	Flagship Ventures Fund V, L.P., By: Flagship Ventures Fund V General Partner LLC, its general partner, By: /s/ Noubar B. Afeyan Ph.D., Title: Manager	12/03/2020
	Flagship Ventures Fund V General Partner LLC, By: /s/ Noubar B. Afeyan Ph.D., Title: Manager	12/03/2020
	Flagship Pioneering Special Opportunities Fund II, L.P., By: Flagship Pioneering, Inc. its manager, By: /s/ Noubar B. Afeyan Ph.D., Title: CEO, Flagship Pioneering, Inc.	12/03/2020
	Flagship Pioneering Special Opportunities Fund II General Partner LLC, By: /s/ Noubar B. Afeyan Ph.D., Title: Manager	12/03/2020
	Flagship Pioneering, Inc., /s/ Noubar B. Afeyan Ph.D., Title: CEO	12/03/2020
	/s/ Noubar B. Afeyan Ph.D.	12/03/2020
	** Signature of Reporting Person	Date
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