AMG 330, the first CD33 × CD3 BiTE applied for acute myeloid leukemia (AML) patients, has shown promising cytolytic activity against AML cells in preclinical studies even at low CD33 antigen densities on target cells, making it a candidate for targeting a broad range of CD33+ leukemias (33–35). Here, CD33 is linked to acute myeloid leukemia.