In MC38 tumor-bearing mice, treatment with either anti-CTLA-4 or anti-PD-1 antibodies only modestly increased the frequency of effector CD8+ and CD4+ T cells amongst TIL, whereas combination treatment had a more significant effect (550% and 330% increases, respectively, relative to control treatment, p<0.01, Fig 3A). This evidence concerns the gene PDCD1 and neoplasm.