BMS-214662 treatment induces apoptosis in both CD34⁺38⁻ and CD34⁺38⁺ CML cells. (A) Representative FACS dot plot showing the sort gate for CD34⁺38⁻ cells (boxed region; i). CD34⁺38⁻ (■) and CD34⁺38⁺ (□) cells were treated for 48 hours with no drug (1), BMS-214662 (2), IM (3), dasatinib (4), nilotinib (5), and lonafarnib (6) and activation of caspase-3 was analyzed by FACS (n = 3). The BMS-214662–treated arm showed a highly statistically significant (**) increase in caspase-3 activation in comparison with the no-drug control (P < .005; ii). (B) CD34⁺ CML cells (n = 3) were treated with BMS-214662 or BMS-225975 (250nM) for 24 hours and annexin V–positive cells (%) were measured by FACS as an indicator of apoptosis. *Differences that are statistically significant (P < .005). Error bars represent ± SD. (C) CD34⁺ normal (i-iii) and CML (iv-vi) cells (n = 3) were untreated (i,iv) or treated with 62.5nM BMS-214662 (ii,v), 250nM BMS-214662 (iii,vi), or 250nM BMS-225975 (vii) and cell-cycle analysis was performed using PI and FACS.