In myeloid neoplasms other than AML, NPM1 mutation has been detected in MDS (2%) and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) (3%), with MDS/MPN represented by mainly chronic myelomonocytic leukemia (CMML). The gene discussed is NPM1; the disease is chronic myelomonocytic leukemia.