To be used in conjunction with Caymans endothelial lipase polyclonal antibody (Item No. 100030) to block protein-antibody complex formation during analysis for the endothelial lipase Endothelial lipase (EL) is a member of the triglyceride lipase gene family. It functions primarily as a phospholipase and has low triglyceride lipase activity. It has been shown to be a major genetic determinant for concentration, structure, and metabolism of high-density lipoprotein, which protects against atherosclerosis. 1,2 It was originally cloned from endothelial cells and was found to be expressed in a distinct and complementary tissue-restricted fashion, with high-level expression in the liver, placenta, lung, ovary, placenta, and macrophage.3 The wide sprEAd distribution of this protein suggests that it plays a general role in lipid metabolism. Immunohistochemical studies demonstrate that EL is expressed in infiltrating cells such as macrophages within atheromatous plaques, in addition to endothelial and smooth muscle cells in non-atherosclerotic coronary arteries. Furthermore, EL expression is detected in the neovasculature within atheromatous plaques in atherosclerotic coronary arteries, indicating that EL may have unique functional roles in atherosclerosis.4 Human endothelial lipase has an estimated molecular weight of 57 kDa.