PBX1 and acute lymphoblastic leukemia: In addition, the mutational landscapes of BCP ALL subtypes defined by ETV6-RUNX1, TCF3-PBX1, TCF3-HLF, high hyperdiploidy (51–67 chromosomes), hypodiploidy (<45 chromosomes) or MLL (also known as KMT2A) rearrangements have been delineated using high-resolution sequencing techniques9, 10, 11, 12, 13.