Fibronectins are disulfide-linked, dimeric glycoproteins of ~440kDa. They possess at least four binding sites for collagen, glycosaminoglycans, transglutaminase, and a cell surface receptor. Epitope of this MAb is located in the 29kDa N-terminal fibrin- and heparin-binding domain of fibronectin. It does not cross-react with MMP-2, MMP-9, or TIMP-2. Fibronectins are involved in cell adhesion, tissue organization, and wound healing. Fibronectins are present in basement membranes, interstitial connective tissue matrix, and blood. Cellular fibronectin is widely distributed in the stroma of many malignant tumors.