As noted earlier, given the limited clinical efficacy of checkpoint inhibitors in AML as a single agent, researchers are now looking into combinatorial approaches with other anti-cancer modalities such as the hypomethylating agent, azacitidine, which is known to upregulate PD-1 and PD-L1 expression (clinicaltrials.gov identifier: 02775903, 03092674) (119). This evidence concerns the gene CD274 and acute myeloid leukemia.