We then determined whether integrin α9β1 depletion modulated the development of atherosclerotic plaque by inducing hypercholesterolemia with intravenous injection of AAV8-PCSK9 to Itga9WT and Itga9KO mice, followed by feeding a HFD for 16 weeks. This evidence concerns the gene PCSK9 and familial hypercholesterolemia.