CD33 and acute myeloid leukemia: Given the high frequency of senescent-like T cells in the BM of patients with AML (10), we next investigated in vitro cytotoxicity of flow-sorted, BM-derived senescent-like (CD3+CD8+CD57+KLRG1+) and nonsenescent (CD3+CD8+CD57–KLRG1–) T cells against autologous AML blasts using an anti–CD3/CD33 bispecific T cell engaging (BiTE) antibody construct (22, 23).