 Current guidelines for managing Philadelphia-positive chronic myeloid leukemia include monitoring the expression of the BCR-ABL1 (breakpoint cluster region/c-abl oncogene 1, non-receptor tyrosine kinase) fusion gene by quantitative reverse-transcription PCR (RT-qPCR).     ///    Our goal was to establish and validate reference panels to mitigate the interlaboratory imprecision of quantitative BCR-ABL1 measurements and to facilitate global standardization on the international scale (IS).     ///    Establishment and validation of analytical reference panels for the standardization of quantitative BCR-ABL1 measurements on the international scale..     ///    "For most methods, percent ratios for BCR-ABL1 e13a2 and e14a2 relative to ABL1 or BCR were robust at 4 different levels and linear over 3 logarithms, from 10% to 0.01% on the IS. "    ///    "The synthetic calibrator panels are robust, reproducibly manufactured, analytically calibrated to the WHO primary standards, and compatible with most BCR-ABL1 RT-qPCR assay designs. "    ///    "The broad availability of secondary reference reagents will further facilitate interlaboratory comparative studies and independent quality assessment programs, which are of paramount importance for worldwide standardization of BCR-ABL1 monitoring results and the optimization of current and new therapeutic approaches for chronic myeloid leukemia.. "