Fibronectin is a high molecular weight glycoprotein containing about 5% carbohydrate that binds to receptor proteins that span the cells membrane, called integrins. In addition to integrins, they also bind extracellular matrix components such as collagen, fibrin and heparin. Fibronectin can be found in the blood plasma in its soluble form which is composed of two 250 kDa subunits joined together by disulfide bonds. Plasma fibronectin is made in the liver by hepatocytes. The insoluble form that serves as a linker in the extracellular matrix is a large complex of cross-linked subunits. Fibronectin is involved in many cellular processes, including tissue repair, embryogenesis, blood clotting, and cell migration/ adhesion, so it can be used as a therapeutic agent for wound healing. It is also one of the few proteins for which production increases with age without any associated pathology. Fibronectins bind cell surfaces and various compounds including collagen, fibrin, heparin, DNA, and actin. Fibronectins are involved in cell adhesion, cell motility, opsonization, wound healing, and maintenance of cell shape. Anastellin binds fibronectin and induces fibril formation. This fibronectin polymer, named superfibronectin, exhibits enhanced adhesive properties. Both anastellin and superfibronectin inhibit tumor growth, angiogenesis and metastasis. Anastellin activates p38 MAPK and inhibits lysophospholipid signaling.