The <i>APOE</i> ε4 allele was associated with all-cause dementia in a dose-dependent fashion (<i>APOE</i> ε4/ε4: Hazard ratio [HR] 2.7, 95% CI 1.7-4.2, <i>P</i> < 0.0001; <i>APOE</i> ε4/ε3: HR 1.5, 95% CI 1.2-1.8, <i>P</i> < 0.001; Cox multivariable regression models adjusted for age at recruitment, gender, genetic principal components 1-10, and genetic ancestry; all models used <i>APOE</i> ε3/ε3 as reference). The gene discussed is APOE; the disease is dementia.