NPM1 and acute myeloid leukemia: Previous studies have focused on several selected genes, for example, FLT3-ITD, NPM1 and CEBPA mutations have been incorporated in the European LeukemiaNet (ELN) risk classification system [6].A recent study by Hou and colleagues [7] reported that IR-AML patients could be re-stratified into three distinct prognostic groups according to the mutation status of FLT3-ITD, NPM1, CEBPA, IDH2, WT1, ASXL1, RUNX1 and DNMT3A.