NPM1 and myeloid neoplasm: Indeed, NPM1, but not FLT3-ITD, was recognized as a provisional entity in the 2008 World Health Organization classification of myeloid neoplasms.68 However, although FLT3-ITD has no capacity of NPM1 mutation to transform a normal hematopoietic cell into a leukemic one, whenever both mutations coexist, the favorable prognostic effect of NPM1 mutation is overridden by the deleterious prognostic effect of FLT3-ITD.