In the settings of myelodysplastic syndrome (MDS) or myelodysplastic syndrome/myeloproliferative neoplasms (MDS/MPN), independent studies have suggested that the presence of NPM1 mutation should be an AML-defining mutation, irrespective of the blast percentage, since these patients benefit from AML-type treatment with intensive chemotherapy (58, 59). The gene discussed is NPM1; the disease is myeloproliferative neoplasm.