Tenascin-C is a hexameric extracellular matrix glycoprotein with multiple isoforms resulting from alternative splicing. Synthesis of tenascin-C occurs in the nervous system, the vasculature and connective tissue components of a number of organs, particularly during development and pathology. Most cells do not express tenascin-C constitutively but expression is induced by growth factors and hormones, such as transforming growth factor-beta and interleukin-l. Tenascin-C is anti-adhesive, but nevertheless is able to influence the differentiation of a variety of cell types. Selective expression of tenascin-C in tumours has led to development of radiolabelled monoclonal anti-tenascin-C antibodies for targeting tumour therapy, with promising results thus far in clinical trials. (C) 1997 Elsevier Science Ltd.