ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: In addition to the technical limitation in the detection of very low levels of BCR-ABL1 transcripts, another pitfall of RT-qPCR seems to lie in the different efficiency of amplification of the e14a2 transcript variant as compared to the shorter e13a2—a problem that might negatively impact the clinical management of CML patients [40].