**2.4 CD123 (IL3Rα)**

Approximately 45% of AML cells that overexpress CD123 have higher proliferative activity and are more tolerant to apoptotic stimulation. Clinical studies have also demonstrated patients overexpressing CD123 usually have a poor prognosis. Williams et al. found that NK-92 preferentially inhibits leukemic stem cells compared with bulk leukemia cells [21]. NK-92 combined with the anti-CD123 antibody, 7G3, enhanced survival in a primary AML xenograft model when compared with control arms. Some other IL3R antibodies (DT388IL3, CSL362, and MGD006) can significantly prolong the survival rate of patients with AML [22, 23].
