APOE and Alzheimer disease: The 36-kDa/34-kDa ratio was again lower in AD compared with control samples (p < 0.001, Fig. 5F), and this difference was maintained when the samples were separated by genotype (AD vs controls for APOE ε3/ε3, p=0.02, and for APOE ε3/ε4, p=0.03) (Fig. 5G).