The last two issues allow to overcome the RT-qPCR limitations in monitoring several fusion transcripts, such as both canonical and atypical BCR–ABL1 breakpoints in CML patients [16] and PML/RARA in acute promyelocytic leukemia (APL) [17], guiding the therapeutic strategy. This evidence concerns the gene ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive.