APOE and atherosclerosis: Atherosclerosis is now recognized as a chronic inflammatory disease in the walls of arteries, and both the innate and adaptive immune systems participate in its pathogenesis.[1–5] The models of low-density lipoprotein receptor–deficient mice (Ldlr−/−) and apolipoprotein E–deficient mice (ApoE−/−) have established the vital role of T cells in the atherosclerotic process.[6–8] In the early stage of atherosclerosis, leukocytes (especially T cells) and monocytes adhere to the injured vascular bed lining and transmigrate into the subendothelial space.