The CD33/CD123 NANOBODY TCE exhibited superior therapeutic potential, demonstrating: (1) enhanced cytolytic activity against CD33+/CD123+ leukemic cells compared to single-target TCEs; (2) favorable pharmacokinetic and pharmacodynamic profiles in nonhuman primate models with minimal toxicity; and (3) effective induction of apoptosis in both bulk AML blasts and CD34+ leukemic stem cells [188]. Here, CD33 is linked to acute myeloid leukemia.