Cholesteryl palmitic acid is a cholesteryl ester. A cholesteryl ester is an ester of cholesterol. Fatty acid esters of cholesterol constitute about two-thirds of the cholesterol in the plasma. Cholesterol is a sterol (a combination of steroid and alcohol) and a lipid found in the cell membranes of all body tissues and transported in the blood plasma of all animals. The accumulation of cholesterol esters in the arterial intima (the innermost layer of an artery, in direct contact with the flowing blood) is a characteristic feature of atherosclerosis. Atherosclerosis is a disease affecting arterial blood vessels. It is a chronic inflammatory response in the walls of arteries, in large part to the deposition of lipoproteins (plasma proteins that carry cholesterol and triglycerides).