Of note, NPM1-mutated AML, usually de novo, showing unique genetic, pathologic, immunophenotypic and clinical features, has now been recognized as a full distinct entity among AML with recurrent genetic abnormalities in the 2016 revision of WHO classification of myeloid neoplasms (MNs) and acute leukemia [21]. This evidence concerns the gene NPM1 and Melnick-Needles syndrome.