APOE and Alzheimer disease: This correlation was also significant in all the AD subjects subgrouped by APOE genotypes: ε3/ε3 (R = 0.61, p = 0.016), ε3/ε4 (R = 0.85, p < 0.001), and ε3/ε4 (T-tau with 180-kDa reelin: R = 0.59, p = 0.025).