Currently, our clinical use of genetics in AML for prognostication relies on (1) the use of cytogenetics to delineate patients into favorable, intermediate, or adverse cytogenetic categories and (2) molecular genotype of the genes FLT3, NPM1 (nucleophosmin 1), and CEBPA (CCAAT/enhancer-binding protein alpha) for those patients with a normal karyotype. The gene discussed is NPM1; the disease is acute myeloid leukemia.