Fibronectins are diverse high molecular weight cell adhesion glycoproteins found in basement membranes, in the interstitial connective tissue matrix, and in soluble in plasma and other body fluids. In adult tissues most fibronectin is produced by hepatocytes (pFn) that differ from locally produced cellular fibronectins. A monoclonal antibody (BF12) has been produced to fibronectin that reacts with both the cellular and plasma forms of the protein and recognizes the cell-binding region in fibronectin. The monoclonal antibody DH1 recognizes only cellular form of Fibronectin. DH1 is specific to the extra domain A (EDA) of the molecule. cFns are found in some basement membranes during development and only in distinct tissues in adult, for instance in smooth muscle and alveolar walls of airways. cFns are abundant in the plasma of carcinoma patients and in the stroma of various carcinomas.Synonyms: CIG, Cold-insoluble globulin, FN1