KMT2A and acute myeloid leukemia: Traditionally, sub-classification and treatment stratification of AML patients was based on criteria including cytogenetic profile, ranging from chromosomal translocations associated with favourable prognosis [e.g., t(8;21)(q22;q22.1);RUNX1/RUNX1T1], to more adverse cytogenetics (e.g., rearrangements of mixed lineage leukaemia (MLL-r) gene on chromosome 11q23 and complex karyotypes).