Inhibition of bromodomain proteins in antigen presenting cells is shown herein to be more inflammatory, to display lower expression of the immunosuppressive molecule PDL1, and to be capable of restoring the responsiveness of tolerant T-cells. Therefore, disclosed is a method for promoting T-cell activation during cancer immunotherapy in a subject that involves administering to a subject undergoing cancer immunotherapy a composition comprising a bromodomain inhibitor. Also disclosed is a method for treating cancer in a subject, comprising co-administering to the subject a bromodomain inhibitor and an immunostimulatory agent.
