APOE and Mental deterioration: Some studies suggest strong associations between APOE ε4 and rate of cognitive decline in Hispanic16,18,19 and African American populations,20 whereas other studies report no significant associations between APOE ε4 and cognition in these groups.21,22,23 As a result, relations among APOE (especially APOE ε2) and cognition in racially and ethnically diverse groups remain unclear.