APOE and Alzheimer disease: A total of 383 AD patients were enrolled in this study, 125 cases (32.6%) carried APOE ε4, among whom four cases (1.0%) carried the APOE ε2/ε4, 96 cases (25.1%) carried the APOE ε3/ε4, and 25 cases (6.5%) carried the APOE ε4/ε4.