Biological Activity of Cytokines: an Evolutionary Perspective

It appears evident that teleost fish are at present the vertebrate group in which, excluding mammals, most information on the immune system is available. However, despite the great impetus on the discovery of genes homologous to mammalian immunomodulatory molecules, the knowledge on biological activities exerted by cytokines is meager. This review reports the present knowledge on the biological activities of cytokine-like and cytokines in invertebrates and cold-blooded vertebrates.