Mutation in BCR-ABL, MLL-AF9, MLL-AF4, MLL-EN6, t(1;19), & t(12;21) The MLL gene from human chromosome 11q23 is involved in >30 different chromosomal translocations resulting in a plethora of different MLL fusion proteins. Each of these tends to associate with a specific leukaemia type, for example, MLL–AF9 is found mainly in acute myeloid leukaemia