Diagram showing absolute Bcr-Abl levels in PB and BM samples.

The ratios of Bcr-Abl/GAPDH at start, after 2 weeks (2W), 4 weeks (4W), and at the time of best response (best) during imatinib therapy are depicted on a logarithmic scale for good responders (●) and poor responders (▴) separately. The medians are represented by lines, and negative PCR results are shown (○) at the level of the particular sensitivity of the PCR reaction.