In CRR 4AgeAccelGrim – which included history of hypertension, diabetes, cardiovascular or cerebrovascular disease as covariates – only APOE ɛ4 carrier status (HR 0.41 (0.27, 0.64), p < 0.001) and smoking status (HR 1.69 (1.05, 2.73), p = 0.03) reached statistical significance, with negative APOE ɛ4 carrier status reducing risk for incident dementia and never-smoking status increasing the risk for incident dementia. The gene discussed is APOE; the disease is diabetes mellitus.