Comparison of BCR-ABL and transport gene transcript levels in CD34⁺ cells from IM responders and nonresponders. (A) Comparison of BCR (left panel) and BCR-ABL (right panel) transcript levels in CD34⁺ CML cells from IM responders (n = 9) and nonresponders (n = 14) relative to BCR transcript levels in CD34⁺ cells isolated from normal persons (n = 6). (B) Comparison of ABCG2 (left panel), ABCB1/MDR (middle panel), and OCT1 (right panel) transcript levels relative to GAPDH transcripts in CD34⁺ CML cells from IM responders and nonresponders. (♦) Results obtained from the 3 patients who rapidly developed BC. Each data point represents the average of a triplicate quantitative RT-PCR measurement of each transcript normalized as described in “Methods.” Cross bars represent the mean ± SEM of data for each patient group. The differences between the results for IM responders and nonresponders are not significant (P > .05).