Notably in these studies, almost half of infant AML cases (0–1 years old) carry KMT2A rearrangements, with a significant proportion bearing the t(9;11)/KMT2A/MLLT3 (MLL/AF9) fusion gene, the incidence of which declines during childhood and adolescence [121]. This evidence concerns the gene MLLT3 and acute myeloid leukemia.