Elevated expressions of PD-1, PD-L1, and PD-L2 were associated with worse OS in AML patients (41), while the inhibition of the PD-1/PD-L1 pathway combined with hypomethylating agents or chemotherapy was found to be feasible and effective for newly diagnosed and refractory/relapsed (R/R) AML patients (3). This evidence concerns the gene PDCD1 and acute myeloid leukemia.