To interrogate the correlation between proportion of AFR, AD neuropathology, clinical decline, and APOE4 risk, we have expanded our original clinicopathological cohort sixfold (1333 individuals over 50 years of age) to obtain the necessary power of analysis to investigate only cases showing evidence of AD-related neuropathological changes or a lack of neuropathological diagnosis (N = 400). Here, APOE is linked to Alzheimer disease.