APOE and Alzheimer disease: This reduced longevity reflects the effect of genotype on risk of age-related cognitive decline and Alzheimer’s disease (AD), with APOE3/E4 (20% Caucasians) and APOE4/E4 (1%–2% Caucasians) individuals at approximately 4- and 15-fold increased risk of AD with a 10–20 years earlier age of onset [57].