KMT2A and acute myeloid leukemia: Elderly AML patients seem to have more chemoresistant disease than younger patients; this is at least partly due to a lower frequency of low-risk genetic abnormalities and a higher frequency of at least certain high-risk abnormalities in elderly patients [1, 6] although some high-risk abnormalities (e.g. MLL abnormalities) do not show such age-dependent differences [44].