“Cholesterol” — a lipid used in the construction of cell membranes and as a precursor in the synthesis of steroid hormones. Dietary cholesterol is obtained from animal sources, but cholesterol is also synthesized by the liver. Cholesterol is carried in the blood by lipoproteins (e.g., LDL and HDL). In atherosclerosis, cholesterol accumulates in plaques on the walls of some arteries.