[Extracellular matrix].

Extracellular matrix is composed of four families: collagens, proteoglycans, elastin and extracellular matrix structural glycoproteins. The extracellular matrix should not be viewed as merely providing strength and physical support for tissues and organisms. It is now quite clear that this matrix exerts profound influence on both the behaviour (e.g. adherence, spreading, and migration) and the pattern of gene expression of the cells. Extracellular matrix research is an active field in biology.