KMT2A and acute myeloid leukemia: Although the World Health Organization (WHO) 2017 guidelines only included MLLT3::KMT2A t(9;11)(p21.3;q23) as an AML-specific gene fusion, there are now over 90 different KMT2A fusion partners listed in the 2022 WHO guidelines, with recommendation to label any KMT2A rearrangement as an AML defining aberration.