IDH2 and acute myeloid leukemia: We found EM AML to be significantly associated with AML-M5 as well as mutations of NPM1, PTPN11 and FLT3-ITD while it was less frequent in AML with mutated IDH2 or CEBPA. For patients harboring EM AML, mutations in TP53 and IKZF1 were found to be independently associated with poor outcome.