NPM1 and myelodysplastic syndrome: Patients who are categorized in this subgroup and have a normal karyotype should be analyzed for FLT3, NPM1, and CEBPA mutations, frequency of which is approximately 20%, 30% and 9%, respectively, in de novo AML-MRC with MLD features and approximately 7%, 12% and 7%, respectively, in AML-MRC supervening after a previous history of MDS or with MDS related cytogenetics.14,17 As a consequence of such a complex scenario some authors proposed to omit the group of patients classified as AML-MRC only on the basis of MLD features.