FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * FORMELA JEAN FRANCOIS   2. Issuer Name and Ticker or Trading Symbol ARCA biopharma, Inc. [ABIO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O ATLAS VENTURE FUND VII, L.P., 25 FIRST STREET, SUITE 303 3. Date of Earliest Transaction (Month/Day/Year) 02/10/2012 (Street) CAMBRIDGE, MA 02141 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Option to Purchase Common Stock

$ 1

02/10/2012

A

3,500

02/10/2012

02/10/2022

Common Stock

3,500

$ 0

3,500

I

See footnote (1) (1)

Option to Purchase Common Stock

$ 1

02/10/2012

A

3,500

(2)

02/10/2022

Common Stock

3,500

$ 0

3,500

I

See footnote (1) (1)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
FORMELA JEAN FRANCOIS C/O ATLAS VENTURE FUND VII, L.P. 25 FIRST STREET, SUITE 303 CAMBRIDGE, MA 02141	X	X

Signatures

/s/ Frank Castellucci, Attorney-in-Fact		02/14/2012
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	This option was granted to Jean-Francois Formela, a director of the issuer. The proceeds of any sale of the issuer's common stock issued to Dr. Formela upon the exercise of this option will be transferred to Atlas Venture Advisors, Inc. ("Atlas Advisors") and therefore Dr. Formela disclaims beneficial ownership of such shares which belong to Atlas Advisors.
(2)	The options vest in 12 equal monthly installments measured from 1/1/12. If the Reporting Person's service as a director of the Issuer terminates in connection with or at anytime following a change in control (for whatever reason), then any unexpired options that remain unvested shall become fully vested.

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