CD105, also known as endoglin, is a 90 kDa type II transmembrane glycoprotein that is expressed on the cell surface as a disulfide-linked homodimer and is found on endothelial cells. CD105 is one of several receptors for the various isoforms of TGF which in turn is one of a family of proteins involved in regulation of cell differentiation, migration of cells, and control on the immune response.