CD4 and acute myeloid leukemia: The combination of LAG-3 and MHC II on CD4+ T cells induces an inhibitory pathway mediated by the activation of immune body tyrosine kinase [48], inhibits the immunity of T cells so that targeting the LAG-3/MHC II signaling pathway helps to promote the immune effect of CD4+ T cells against tumors, indicating that LAG-3 is critical for Treg-mediated immunosuppression and may serve as a novel therapeutic strategy in AML.