In particular, in vivo experiments have demonstrated the therapeutic efficacy of using IFN-α to treat viral infections, such as respiratory tract infections in cattle, transmissible gastroenteritis or rotavirus diarrhea in pigs, and other viral infections in mice, as well as immune-mediated diseases, such as polymyositis, multiple sclerosis and experimental autoimmune allergic encephalomyelitis in rats and mice [13,14]. This evidence concerns the gene IFNA2 and viral infectious disease.