AbstractINTRODUCTIONThe interactions between cells and their extracellular matrices are controlled by various intracellular and exogenous signals. The control of these interactions by polypeptide growth factors appears to involve different levels of regulation. Growth factors can, in addition to the regulation of cell proliferation, direct cell migration and movement, alter the production of different connective tissue components, and regulate extracellular proteolysis. Of particular interest are the autocrine and paracrine growth factors produced by both normal and malignant cells (1-5).