The MaxDiscovery™ Human TRAIL/TNFSF10 ELISA Test Kit is designed for quantitative determination of the concentration of human TRAIL/TNFSF10 in serum, plasma, and cell culture supernatant. TNF-related apoptosis-inducing ligand (TRAIL), a tumor necrosis factor superfamily (TNFSF) member designated TNFSF10, is a 281 amino acid protein which lacks a signal peptide. It is a Type II transmembrane protein consisting 3 domains, a glycosylated C-terminal extracellular domain, a transmembrane domain, and a short N-terminal cytoplasmic domain. Like other members of the TNFSF, TRAIL also exists in a soluble form. It has a broad expression pattern in fetal and adult tissues and variably expressed in tumor cell lines. Both cell-surface and soluble TRAIL induce apoptosis in a variety of lymphoid and non-lymphoid tumor cell lines. These effects are mediated through binding TRAIL receptors 1 and 2 (TRAIL R1 and TRAIL R2). Since TRAIL is capable of preferentially inducing apoptosis in tumor cells over normal cells, it has become an exciting prospect as a cancer pharmaceutical.