LDL (low-density lipoproteins) are complexes of a single molecule of apoprotein B-100 (apoB-100) non-covalently associated with triacylglycerol, free cholesterol, cholesterol esters, and phospholipids.Clearance of LDL from the blood involves binding to LDL receptors associated with coated pits at the cell surface, forming complexes that are internalized and passed via clathrin-coated vesicles to endosomes, where they dissociate. The LDL particles move into lysosomes and are degraded while the LDL receptors are returned to the cell surface. This process occurs in most cell types but is especially prominent in hepatocytes. It plays a major role in returning cholesterol from peripheral tissues to the liver (Hobbs et al. 1990).