APOE and Mental deterioration: The cumulative incidence of cognitive decline to age 85 years was estimated to be 37.2% (CI 36.4–41.0) in APOE ε3/ε3 homozygotes, 35.3% (CI 30.5–39.6) in ε2/ε2 homozygotes, 45.7% (CI 46.5–53.9) in ε3/ε4 heterozygotes and 52.9% (CI 46.1–76.2) in ε4/ε4 homozygotes (Figure 2a, Table S7).