KMT2A and leukemia: By driving expression of genes such as the Hox genes and Meis1, MLL-fusions confer cells with stem cell-like properties (Zeisig et al., 2004), including acquisition of self-renewal capacity in otherwise short-lived lineage-committed HPCs which can then function as potent leukemia stem cells (LSCs) (Cozzio et al., 2003; Krivtsov et al., 2006; Ugale et al., 2014, 2017).