The relationship between topoisomerase 2 (topo 2) inhibitor therapy and the pathogenesis of treatment-related acute myeloid leukaemia (t-AML) with rearrangements of the mixed lineage leukaemia (MLL) gene is now well documented (Felix, 1998; Pui and Relling, 2002). This evidence concerns the gene KMT2A and acute myeloid leukemia.