For example, the effects of the APOE4 allele on AD risk are greatest in younger individuals, with the risk of AD among Caucasian APOE3/4 individuals peaking at age 65 (OR ~ 4) and the risk of AD among Caucasian APOE4/4 individuals peaking at age 60 (OR ~ 15.5) [7]. Here, APOE is linked to Alzheimer disease.