PDCD1 and acute myeloid leukemia: Interestingly, the combination of anti–hPD-1H mAbs and anti–hPD-1 mAbs resulted in complete rejection of AML tumors (mean AML tumor volume ± SEM [on day 9] was 44.4 ± 23.3 mm3 in THP WT treated with isotype, 33.6 ± 16.8 mm3 in THP1 WT treated with anti–PD-1, 14.5 ± 9.8 mm3 in THP1 WT treated with anti–PD-1H, 11.1 ± 11.1 mm3 in THP1 WT treated with the combination of anti–PD-1 with anti–PD-1H; n = 5) (Figure 7).