Concerning the association of ApoE ε4 with the risk of AD, a meta-analysis of clinical- and autopsy-based studies demonstrated that, compared with individuals with an ε3/ε3 genotype, the risk of AD was increased in carriers of ApoE ε4/ε4 (OR 14.9) among Caucasian subjects [33], but this association was weaker among African Americans [33]. Here, APOE is linked to Alzheimer disease.