ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: The majority of CML patients carry a “canonical” t(9;22) translocation characterized by chromosomal breakpoints located on exon 13 or 14 of the BCR gene and on exon 2 of the ABL1 gene (respectively, the e13a2 and e14a2 fusion transcripts) [2].