APOE and Alzheimer disease: ApoE at 236 position is not only close to the lipid-binding region (244–272) and it is localized within a region (230–243) that is vital for ApoE oligomerization and Aβ binding (Frieden and Garai, 2012), suggesting that the AD protective effect of APOE3-V236E mutation may be achieved through regulation of lipid metabolism, ApoE aggregation, and Aβ clearance.