APOE and Alzheimer disease: In addition, a number of these studies have also reported that APOE4− AD patients possess relatively more pronounced deficits in non-memory cognitive domains, such as executive function, visuospatial abilities, and language, than APOE4+ AD patients [48, 51–58], with a greater effect observed in younger APOE4− vs. APOE4+ AD patients [54, 58] (Table 2).