NPM1 and leukemia: When injected to immunocompromised mice, NPM1-mutated leukemic cells can generate leukemia.64 The NPM1 mutation is stable at diagnosis and relapses and is therefore considered a potential marker for minimal residual disease (MRD).65 On the contrary, FLT3-ITD is recognized as a late event,66 may be sub-clonal,67 and is therefore not reliable as an MRD marker.