RUNX1 and acute lymphoblastic leukemia: Six major genetic subtypes, altogether accounting for 70% to 75% of BCP-ALL, have been defined by high hyperdiploidy (51 to 67 chromosomes per leukemic cell), hypodiploidy (fewer than 45 chromosomes per leukemic cell), andETV6-RUNX1,TCF3-PBX1,BCR-ABL1, andKMT2A gene-involving fusions.