HAVCR2 and acute myeloid leukemia: AML blasts have demonstrated a proclivity for immune evasion through the downregulation of MHC molecules while continuously expressing immune checkpoint ligands such as programed death-ligand 1 (PD-L1), B7-H3, lymphocyte-activation gene 3 (LAG3), TIM3, galectin 9 (Gal-9), and cytotoxic T cell lymphocyte associated protein 4 (CTLA-4) [174,175,176,177].