Key enzyme in triglyceride metabolism. Catalyzes the hydrolysis of triglycerides from circulating chylomicrons and very low density lipoproteins (VLDL), and thereby plays an important role in lipid clearance from the blood stream, lipid utilization and storage (PubMed: 8675619, PubMed: 11342582, PubMed: 27578112). Although it has both phospholipase and triglyceride lipase activities it is primarily a triglyceride lipase with low but detectable phospholipase activity (PubMed: 7592706, PubMed: 12032167). Mediates margination of triglyceride-rich lipoprotein particles in capillaries (PubMed: 24726386). Recruited to its site of action on the luminal surface of vascular endothelium by binding to GPIHBP1 and cell surface heparan sulfate proteoglycans (PubMed: 11342582, PubMed: 27811232).