KMT2A and acute lymphoblastic leukemia: The World Health Organization (WHO) recognizes nine different sub-entities within the BCP-ALL with recurrent genetic abnormalities [8], including 4 groups characterized by the specific translocations, which result in the formation of aberrant chimeric transcripts detectable by RNA-Seq fusion calling (BCR-ABL1, KMT2A-rearranged, ETV6-RUNX1, TCF3-PBX1).