Fig. 3.

Diagrams of several models depicting the possible relation of extracellular matrix (ECM) molecules to the cell surface. All models envision plasma membrane receptors for one or more molecules. CO, collagen; FN fibronectin; PG, proteoglycans; HA, hyaluronic acid. A: Model based on the data from Sugrue and Hay (1982). B: Model based on data from Singer (1979) and Kleinman et al. (1981). C: Model of FN interaction with fibroblasts by Hynes et al. (1982). D: Model of glycosaminoglycans and the mesenchymal cell surface from Toole (1981). Reprinted from Hay, (1981a,b).