Effects of KW-2449 on human leukemia cells without FLT3 mutation. (A) RS4;11 cells, which express wild-type FLT3/ITD, were treated with KW-2449 at the indicated concentrations for 30 minutes. Total and phosphorylation levels of HH3 were analyzed by Western blotting. (B) RS4;11 cells were treated with various concentrations of KW-2449 for 48 hours, and cell-cycle distribution was analyzed. (C) RS4;11 cells were treated with various concentration of KW-2449 for 48 hours, and apoptosis induction was analyzed.