The 11q23-rearranged AML subgroup represents more than 20% of pediatric cases, with >80 recognized fusion partners, although the majority of leukemias result from KMT2A fusions with one of about six common partner genes, with KMT2A-MLLT3 being the most recurrent, and the prognostic significance is strictly dependent on the fusion partner, with the KMT2A-AFDN fusion associated with a particularly poor prognosis (Balgobind et al., 2009; Coenen et al., 2011; Pigazzi et al., 2011; Manara et al., 2014a; Meyer et al., 2018). This evidence concerns the gene KMT2A and leukemia.