Fibronectin is a glycoprotein present in a soluble dimeric form in plasma, and in a dimeric or multimeric form at the cell surface and in extracellular matrix. Fibronectin is involved in cell adhesion and migration processes including embryogenesis, wound healing, blood coagulation, host defense, and metastasis. They occur as dimers of two 200 kDa subunits. They have binding domains for bacterial proteins, collagens, heparin-like molecules and fibrin. Cellular fibronectin is widely distributed in the stroma of malignant tumours.