APOE and Alzheimer disease: As expected, the percentage of APOE ε4 allele carriers significantly correlated with the level of AD neuropathological changes (ε4+: Not 5.8% vs Low 20.4% vs Intermediate-High 29.7%, p < 0.0005), whereas the APOE ε2 allele carrier status demonstrated a trend towards a lower grade of AD pathology (ε2+: Not 15.0% vs. Low 9.6% vs. Intermediate-High 2.7%, p = 0.056).