Acute myeloid leukemia and related neoplasms are not only classified according to cytogenetic alterations, but also according to specific gene mutations, such as nucleophosmin 1 (NPM1), biallelic mutation of CCAAT/enhancer-binding protein alpha (CEBPA) and tunt-related transcription factor 1 (RUNX1) as provisional entity. The gene discussed is NPM1; the disease is neoplasm.