Exhibit 32.1

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

 

Pursuant to the requirement set forth in Rule 13a-14(b) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and in connection with the Annual Report of Atara Biotherapeutics, Inc. (the “Company”) on Form 10-K for the year ended December 31, 2016, as filed with the Securities and Exchange Commission (the “Report”), Isaac Ciechanover, Chief Executive Officer of the Company, and John McGrath, Chief Financial Officer of the Company, respectively, do each hereby certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1)

The Report fully complies with the requirements of Section 13(a) or 15(d) of the Exchange Act; and

(2)

The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

 

Date: March 9, 2017

 

/s/ Isaac Ciechanover 

Isaac Ciechanover

President and Chief Executive Officer

(Principal Executive Officer)

 

/s/ John McGrath 

John McGrath

Executive Vice President and Chief Financial Officer

(Principal Financial and Accounting Officer)

 

 

This certification accompanies the Annual Report on Form 10-K to which it relates, is not deemed filed with the Securities and Exchange Commission and is not to be incorporated by reference into any filing of the Company under the Securities Act of 1933, as amended, or the Exchange Act (whether made before or after the date of the Form 10-K), irrespective of any general incorporation language contained in such filing.