Vitronectin is a cell adhesion and spreading factor found in serum and tissues. Vitronectin interact with glycosaminoglycans and proteoglycans. Is recognized by certain members of the integrin family and serves as a cell-to-substrate adhesion molecule. Inhibitor of the membrane-damaging effect of the terminal cytolytic complement pathway. Somatomedin-B is a growth hormone-dependent serum factor with protease-inhibiting activity. This is the function of VTN (vitronectin, ENSG00000109072).