IDO1 and acute myeloid leukemia: Although AML blasts may prompt the secretion of pro-inflammatory cytokines, such as tumor necrosis factor-a (TNF-a), IL1b, and IL6, AML blasts also secrete immunoinhibitory factors, such as IL-10, TGF B, IL-35, and indoleamine 2,3-dioxygenase 1 (IDO1) [43,44,45].