In fish models, cytokine induction by microbial/viral infection [e.g., TNFα and interleukins in carp species (42, 43)] and IGF-I modulation by cytokines [e.g., TNFα) have been reported [e.g., in immune cells/tissues of trout and sea bass, see (44) for a recent review]. This evidence concerns the gene TNF and viral infectious disease.