Tumor Endothelial Markers (TEMs, TEM 1-9) are recently identified genes, whose expression is elevated in tumor-associated endothelium. TEMs are barely detectable in normal endothelial cells. TEM8 has been shown to interact with C5 domain of collagen a3(VI), a protein also preferentially expressed in tumor endothelium. It is thoμght that TEM8 may play a role in tumor angiogenesis.