CDKN2A and acute myeloid leukemia: NPM1 mutations, the most common genetic abnormality has been detected in adult de novo AML, are observed in about 30% of AMLs and about 50%-60% CN-AML. 1,3  The NPM1 gene is located on long arm of chromosome 5 at band q35.   4  NPM1 wild type is a Nucleocytoplasmic trafficking protein, with localization in the nucleolus.   1  The important functions of NPM1 are: transport of ribosomal components into the cytoplasm, control of centrosome duplication, reaction with p53, and regulation of ARF-Hdm2/Mdm2-P53 oncogenic suppressor pathway. 1,5