KMT2A and acute lymphoblastic leukemia: Treatment improvement in childhood acute lymphoblastic leukemia (ALL) depends on the assessment of conventional risk factors such as age <1 year or ≥10, white blood-cell (WBC) count ≥50x109/L, detection of extramedullary disease, immunophenotype of T-cells, and presence of the BCR-ABL1 fusion or MLL gene rearrangements, as well as on the detection of novel molecular markers of poor prognosis [1].