Imatinib mesylate suppresses growth of

BCR/ABL-positive LTCICs and CFCs. Total (▪) andBCR/ABL-positive (░) progenitor frequencies (LTCICs and CFCs) for CML CD34⁺ cells exposed to imatinib mesylate for 96 hours are shown. The frequency of BCR/ABL-positive progenitors equals the total number of progenitors times the percentage of cells that were BCR/ABL positive on FISH analysis of pooled colonies. The data plotted are normalized to the number of total progenitors observed in the absence of imatinib mesylate and are shown as the mean ± SEM.