PDCD1 and neoplasm: Although anti-PD-1 treatment in Spata2-deficient tumor-bearing mice exerted a modest, but not significant, effect on delaying tumor growth, more mice achieved a complete (3/23) or partial response (4/23) compared to anti-PD-1 treatment in WT tumor-bearing mice (1/24 CR; 2/24 PR) two weeks post treatment (Figures 5A, B).