Type XIX collagen

Type XIX collagen is a member of the fibril-associated collagens with interrupted triple helices (FACIT) family. It is thought to organize the collagenous extracellular matrix (ECM) through its ability to act as a cross-bridge between fibrils and other ECM molecules. Type XIX collagen is a homotrimer composed of three α1 chains and is expressed in vascular, neuronal, mesenchymal, and epithelial basement membrane zones in the breast, colon, kidney, liver, placenta, prostate, skeletal muscle, skin, and spleen. Type XIX collagen is involved in the development of the brain as well as muscle tissue of the esophagus and the heart. In addition, type XIX collagen is lost during breast cancer progression and harbors signaling domains that may inhibit the growth of melanoma cells. Biomarkers are available for measuring type XIX collagen and have been used to demonstrate elevated circulating levels of type XIX collagen in the serum of non-small-cell lung cancer patients.