The protective bone-marrow microenvironment might also exert an immunosuppressive influence by preventing access of T cells to AML blasts or by secretion of immune-dampening metabolites such as indoleamine 2,3-dioxygenase, 2-hydroxyglutarate, and arginine by the AML blasts [83]. The gene discussed is IDO2; the disease is acute myeloid leukemia.