Our data also suggestedthat Kmt2a breakage itself is not sufficient for the fulldevelopment of infantile leukemia, even if the DNA damage response is defective.Infant leukemia has one of the lowest frequencies of somatic mutations of anysequenced cancer [32].Activating mutation of genes associated with cellular proliferation such as RASmutations has been identified as an one of these mutations. The gene discussed is KMT2A; the disease is leukemia.