RSAD2 and viral infectious disease: Poly(I:C) stimulation up regulated a number of interferon-associated genes, such as CXCL11 (interferon-inducible protein 9), CXCL10 (interferon γ-induced protein 10) and RSAD2 (radical S-adenosyl methionine domain containing 2) as well as OAS2, a gene that encodes a member of the 2-5A synthetase family, which has been involved in the innate immune response to viral infection [19,20].