KMT2A and leukemia: Further studies revealed the ability of these MLL-FPs to efficiently transform hematopoietic cells at different developmental stages (e.g., hematopoietic stem cells, common myeloid progenitors, and granulocyte and macrophage progenitors) into leukemic cells possessing stem-cell-like properties, such as being capable of self-renewal and leukemia initiation and maintenance (Cozzio et al., 2003; Krivtsov et al., 2006, 2008; Krivtsov and Armstrong, 2007).