WHEN DID COMMUNICATION IN THE IMMUNE-SYSTEM BEGIN

Cytokines are a family of regulatory molecules that facilitate the com munication between cells, most especially those of the hemopoietic sys tem and there is evidence that the neuroendocrine system may benefit b y this collaboration as well, Evolutionary evidence indicates that the beginnings of communication between cells with the protozoans as pher omone molecules. These underwent modification to become more akin to t he cytokines of multicellular forms. Since the activities of invertebr ate (ciliate pheromones) cytokines of multicellular forms. Since the a ctivities of invertebrate (ciliate pheromones) cytokines are easily as sayed in vertebrate systems, this suggests that the structure-function relationships of these molecules have been conserved. Cytokines have been present for millions of years in animals and as such, are importa nt, ancient, and functionally conserved host defense molecules.