The MLL H3K4 methyltransferase gene was identified as a recurrent target of chromosomal translocations of the long arm (q) of chromosome 11 at band q23 in acute leukaemias, including infant, paediatric, adult, and therapy-induced AML, ALL, and acute biphenotypic leukaemia (ABL) [79,80,81,82]. This evidence concerns the gene ABL1 and acute lymphoblastic leukemia.