Chronic myeloid leukemia (CML) is well suited to molecular monitoring as rising and falling levels of BCR-ABL transcript, measured by RQ-PCR (real time quantitative polymerase chain reaction) from venous peripheral blood (PB) correlate well with disease progression and remission (1). Fluorescence in situ hybridization (FISH) and classical cytogenetics performed on bone marrow (BM) may have a role (2,3) but neither are as sensitive and reproducible for disease monitoring as RQ-PCR, especially when RQ-PCR is performed within a standardized laboratory with an optimized system(4).