APOE and Alzheimer disease: In a multiple regression of iron in the inferior temporal cortex (including the following covariates: age, sex, APOE ε4, and AD diagnosis; iron was log-transformed for normality then transformed into a Z score for ease of comparison), iron was elevated in AD subjects (β[S.E.] = 0.406 [0.087]; P = 5 × 10−6).