PDCD1 and neoplasm: The combination of anti-PD-1 antibody with entinostat (as positive control) resulted in significant suppression of tumor growth, but no eradication of primary tumors (complete response, CR) in 7 mice, extending survival to 70% at day 42 after tumor implantation when compared with anti-PD-1 antibody (SFig. 1C,D).