CD33 and acute myeloid leukemia: Noteworthy, TIGIT ligands CD112 and CD155 are not only highly expressed on AML cells, but the blockade of the TIGIT/CD112/CD155 axis augments T cell-mediated lysis of AML cells and enhances the cytotoxic effects of the CD33/CD3 bi-specific T cell engager (BiTE)® antibody construct AMG-330 [191,192].