These effect sizes were similar when controlling for the number of APOE ε4 alleles, a well-established genetic risk allele for sporadic, late-onset AD (baseline CN: HR = 1.49, P = 0.005, 95% CI = 1.13 to 1.96; baseline MCI: HR = 1.42, P < 0.001, 95% CI = 1.23 to 1.62). This evidence concerns the gene APOE and Alzheimer disease.