EX-A

EXHIBIT A

Agreement of Joint Filing

The undersigned hereby agree that a single Schedule 13G (or any amendment thereto) relating to the Common Stock of Arcus Biosciences, Inc. shall be filed on behalf of each of the undersigned and that this Agreement shall be filed as an exhibit to such Schedule 13G.

Date: February 11, 2019


GV 2016, L.P.
By:		GV 2016 GP, L.P., its General Partner
By:		GV 2016 GP, L.L.C., its General Partner
By:		Alphabet Holdings LLC, its Sole Member

By:		/s/ Kathryn W. Hall
Name:		Kathryn W. Hall
Title:		Secretary


GV 2016 GP, L.P.
By:		GV 2016 GP, L.L.C., its General Partner
By:		Alphabet Holdings LLC, its Sole Member

By:		/s/ Kathryn W. Hall
Name:		Kathryn W. Hall
Title:		Secretary


GV 2016 GP, L.L.C.
By:		Alphabet Holdings LLC, its Sole Member

By:		/s/ Kathryn W. Hall
Name:		Kathryn W. Hall
Title:		Secretary


GV 2017, L.P.
By:		GV 2017 GP, L.P., its General Partner
By:		GV 2017 GP, L.L.C., its General Partner
By:		Alphabet Holdings LLC, its Sole Member

By:		/s/ Kathryn W. Hall
Name:		Kathryn W. Hall
Title:		Secretary


GV 2017 GP, L.P.
By:		GV 2017 GP, L.L.C., its General Partner
By:		Alphabet Holdings LLC, its Sole Member

By:		/s/ Kathryn W. Hall
Name:		Kathryn W. Hall
Title:		Secretary


GV 2017 GP, L.L.C
By:		Alphabet Holdings LLC, its Sole Member

By:		/s/ Kathryn W. Hall
Name:		Kathryn W. Hall
Title:		Secretary


Alphabet Holdings LLC

By:		/s/ Kathryn W. Hall
Name:		Kathryn W. Hall
Title:		Secretary

Page 18 of 19


XXVI Holdings Inc.

By:		/s/ Kathryn W. Hall
Name:		Kathryn W. Hall
Title:		Assistant Secretary


Alphabet Inc.

By:		/s/ Kathryn W. Hall
Name:		Kathryn W. Hall
Title:		Assistant Secretary