Its popularity owes in large part to the suitability of ApoE−/− mice as an experimental animal model to study the pathogenesis of numerous diseases, as well as the association between APOE polymorphism and a wide spectrum of diseases in humans including coronary and peripheral vascular disease (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13), obesity/diabetes (10, 14, 15), and Alzheimer’s disease (16). Here, APOE is linked to early-onset autosomal dominant Alzheimer disease.