BCR and chronic myelogenous leukemia, BCR-ABL1 positive: Further to this, external quality assessment (EQA) programs have been established to assess the quality of testing [4], For molecular MRD testing, EQA data has shown that interlaboratory variation for molecular AML MRD testing was substantially greater than that seen for BCR::ABL1 testing in chronic myeloid leukemia (CML), despite both tests being reverse transcription quantitative PCR-based (Fig. 1) [5, 6].