Some AML groups, namely t(15;17), t(8;21) and FAB M7, more frequent in children than adults, were clearly distinguished whereas AML with CBFB/MYH11 fusion gene (inv(16)) and KMT2A chimeric fusion genes revealed more heterogeneity, indicating the existence of additional subgroups. This evidence concerns the gene MYH11 and acute myeloid leukemia.