The central role of immunity in the symbiotic event referred as parasitism

Several papers have been published on the communications between species, including hostparasite and predator-prey interactions. Here we stress the crucial role of immune system in symbiosis and parasitism. In particular, it appears that during the coevolution between any interacting populations the immune system was selected accordingly to a flexible strategy in order to adapt itself to the needs of the homeostasis, thus allowing the evolution of symbiotic relationships.