Accordingly, retroviral transduction and genetic editing of human CB with MLL-ENL and MLL-AF9 produces ALL, AML and mixed-lineage leukaemias with the latter fusion and entirely ALLs with MLL-ENL in xenografts, recapitulating the phenotypes of human disease for these two fusions [151,152]. The gene discussed is KMT2A; the disease is acute lymphoblastic leukemia.