Testa and coworkers have explored the possible effects induced by CD123 overexpression at the level of leukemic cells and have shown that: (a) leukemic blasts overexpressing IL-3Rα exhibit higher cycling activity and increased resistance to apoptotic triggering elicited by growth factor deprivation; (b) AMLs overexpressing IL-3Rα frequently display constitutive Stat5 phosphorylation; (c) the incubation of AML blasts displaying high IL-3Rα expression with IL-3 induced Stat5 activation at significantly higher levels than in leukemic cells with normal IL-3Rα levels [35]. This evidence concerns the gene IL3RA and acute myeloid leukemia.