SecProbe.io

Mail Stop 4720

November 1 9, 2015

Via E -mail
Isaac E. Ciechanover, M.D.
Chief Executive Officer
Atara Biotherapeutics, Inc.
701 Gateway Blvd., Suite 200
South San Francisco, California 94080

Re: Atara Biotherapeutics , Inc.
  Registration Statement on Form S-3
Filed  November 9, 2015
  File No.  333-207876

Dear Dr. Ciechanover :

This is to advise you that we have not  reviewed and will not review your registration
statement .

We urge all persons who are responsible for the accuracy and adequacy of the disclosure
in the filing to be certain that the filing includes the information the Securities Act of 193 3 and
all applicable Securities  Act rules require .  Since the company and its management are  in
possession of all facts relating to a company’s disclosure, they are responsible for the accuracy
and adequacy of the disclosures they have made.

In the event you request acceleration of the effective date of the pending regist ration
statement , please provide  a written statement from the company acknowledging that:

 should the Commission or the staff, acting pursuant to delegated authority, declare the
filing effective, it does not foreclose the Commission f rom taking any action with respect
to the filing;

 the action of the Commission or the staff, acting pursuant to delegated authority, in
declaring the filing effective, does not relieve the company from its full responsibility for
the adequacy and accurac y of the disclosure in the filing; and

Isaac E. Ciechanover, M.D.
Atara Biotherapeutics , Inc.
November 1 9, 2015
Page 2

  the company may not assert staff comments and the declaration of effectiveness as a
defense in any proceeding initiated by the Commission or any person under the federal
securities laws of the United States.

Please  refer to Rules 460 and 461 regarding requests for  acceleration .  We will consider a
written request for acceleration of the effective date of the registration statement as confirmation
of the fact that those requesting acceleration are aware of their resp ective responsibilities under
the Securities Act of 1933 and the Securities Exchange Act of 1934 as they relate to the proposed
public offering of the registered securities .

Please  contact Scot Foley at (202) 551 -3383 or me a t (202) 551 -3675 with any questions.

Sincerely,

            /s/ Suzanne Hayes

Suzanne Hayes
Assistant Director

cc: Kenneth L. Guernsey
Jodie M. Bourdet
Cooley  LLP
101 California Street, 5th Floor
San Francisco, California 94111