Lipoprotein lipase is at the center of lipoprotein metabolism, unloading triglycerides for metabolic use in extrahepatic tissues, regulated in concert with energy metabolism by insulin and other factors, and converting the input of large triglyceride-rich lipoproteins to smaller, potentially atherogenic remnants that are either remodeled into LDL and HDL, or quickly cleared. In addition, lipoprotein lipase has turned out to be a multifunctional protein that also acts as a ligand for binding of lipoproteins to proteoglycans and receptors. Hepatic lipase has evolved more recently, and its main role appears to be in the remodeling processes.