BMS-214662 activates catastrophic cell cycle. (A) BMS-214662 (250nM) induced phosphorylation of Cdk2 in CD34⁺ CML cells derived from patients (n = 6; i-ii), whereas BMS-225975 (250nM) did not (n = 3, iii). Percentage of active caspase-3–positive cells is reported (iv). (B) Time course of treatment with BMS-214662 (250nM) in CML CD34⁺ cells showed changes in protein levels after Western blotting analysis (i). Time course of treatment with BMS-214662 (250nM) in normal CD34⁺ cells showed no changes in protein levels after Western blotting analysis (n = 3, ii). SDS gel 4% to 15%.