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* DAG Ventures Management V, LLC (Last) (First) (Middle) 251 LYTTON AVENUE, SUITE 200 (Street) PALO ALTO CA 94301 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 10/15/2014	3. Issuer Name and Ticker or Trading Symbol Atara Biotherapeutics, Inc. [ ATRA ]
		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 Preferred Stock	(1)	(1)	Common Stock	1,278,935	(1)	I	see footnote(2)
Series B Preferred Stock	(1)	(1)	Common Stock	623,863	(1)	I	see footnote(2)
Series A Prefered Stock	(1)	(1)	Common Stock	3,115	(1)	I	see footnote(3)
Series B Preferred STock	(1)	(1)	Common Stock	1,519	(1)	I	see footnote(3)

1. Name and Address of Reporting Person* DAG Ventures Management V, LLC (Last) (First) (Middle) 251 LYTTON AVENUE, SUITE 200 (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* DAG Ventures V-QP, L.P. (Last) (First) (Middle) 251 LYTTON AVENUE, SUITE 200 (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* DAG Ventures V, L.P. (Last) (First) (Middle) 251 LYTTON AVENUE, SUITE 200 (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Goodrich R. Thomas (Last) (First) (Middle) 251 LYTTON AVENUE, SUITE 200 (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Cadeddu John J. (Last) (First) (Middle) 251 LYTTON AVENUE, SUITE 200 (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Williams Greg (Last) (First) (Middle) 251 LYTTON AVENUE, SUITE 200 (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Chung Young J. (Last) (First) (Middle) 251 LYTTON AVENUE, SUITE 200 (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Pianim Nicholas K. (Last) (First) (Middle) 251 LYTTON AVENUE, SUITE 200 (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. Each share of preferred stock will automatically convert into one share of the Issuer's common stock upon the closing of the Issuer's initial public offering. The shares have no expiration date.

2. The shares are held by DAG Ventures V, L.P. DAG Ventures Management V, LLC ("DAG Management V") serves as the sole General Partner of DAG Ventures V, L.P. ("DAG V"). As such, DAG Management V possesses sole voting and investment control over the securities owned by DAG V and may be deemed to have indirect beneficial ownership of the securities held by DAG V. DAG Management V, however, owns no securities of the Issuer directly. Messrs. Cadeddu, Chung, Goodrich, Pianim and Williams are Managing Directors of DAG Management V and share voting and dispositive power over the shares held by DAG V. Each Reporting Person disclaims beneficial ownership of the shares held by DAG V except to the extent of his or its proportionate pecuniary interest therein.

3. The shares are held by DAG Ventures V-QP, L.P. DAG Ventures Management V, LLC ("DAG Management V") serves as the sole General Partner of DAG Ventures V-QP, L.P. ("DAG V-QP"). As such, DAG Management V possesses sole voting and investment control over the securities owned by DAG V-QP and may be deemed to have indirect beneficial ownership of the securities held by DAG V-QP. DAG Management V, however, owns no securities of the Issuer directly. Messrs. Cadeddu, Chung, Goodrich, Pianim and Williams are Managing Directors of DAG Management V and share voting and dispositive power over the shares held by DAG V-QP. Each Reporting Person disclaims beneficial ownership of the shares held by DAG V-QP except to the extent of his or its proportionate pecuniary interest therein.

Remarks:

	/s/ Joseph J. Zanone by power of attorney	10/15/2014
	** Signature of Reporting Person	Date
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