APOE and atherosclerosis: <h4>Introduction</h4>This study investigated the impact of <i>APOE</i> gene polymorphisms on the development of coronary artery disease (CAD) in the Han Chinese population at middle and high altitudes, focusing on lipid level regulation and atherosclerosis.<h4>Methods</h4>This retrospective case-control study involved 628 CAD patients and 628 matched controls without CAD.