NPM1 and acute myeloid leukemia: In the full cohort, using Cox proportional hazard regression and LASSO analyses for age, FLT3 and NPM1 mutation status, cytogenetic risk group, treatment site, race, primary payor, and Charleston Comorbidity Index (CCI), age (HR 65y vs 35y/=2.44, 95% CI 1.61–3.68, p<0.001) was the strongest risk factor in AML.