Since apolipoprotein E (ApoE) polymorphism has been shown as a major risk factor for AD (Corder et al., 1993; Saunders et al., 1993) and ApoE-rich HDL is the major lipoprotein in the central nervous system (CNS; Vance and Hayashi, 2010), the involvement of lipids in the pathogenesis of AD has been investigated. Here, APOE is linked to Alzheimer disease.