By modulating the pool of pro-inflammatory cytokines synthesized by the sensory CVOs, IL-10 could thus play an important role in modulating the duration of sickness responses associated with infection or inflammation, as we and others have shown that the induction of pro-inflammatory cytokines within the brain is a key event in the prolongation of illness-associated fever, anorexia and lethargy[16-18]. This evidence concerns the gene IL10 and infection.