CLU and Alzheimer disease: We isolated and purified DNA from 57 participants to genotype for two genes associated with increased risk of late onset AD: APOE and APOJ. The following numbers of subjects per group were included in analyses: ε2/ε2 (2 subjects), ε2/ε3 (6 subjects), ε3/ε3 (40 subjects), ε3/ε4 (9 subjects) (Table 1).