BCR-ABL transcript levels in bone marrow samples determined by quantitative RT-PCR and given as ratio of BCR-ABL to GAPDH signal. Samples were collected at predefined time points during the study (ie, prior to and after INDII and prior to C1 as shown in Figure 1). Values are depicted on a logarithmic scale for patients treated within the alternating (•) or concurrent (○) schedule, with median values represented by solid lines. Negative RT-PCR results are shown at the level of the sensitivity of the PCR reaction.