The expression pattern of IFN-I in CIK cells is different from that in salmon cells, in which group I IFN-I (IFN-a, IFN-d, and IFN-e) but not group II IFN-I (IFN-b, IFN-c, and IFN-f) are ubiquitously produced and are inducible (IFN-a, IFN-d, IFN-e, and IFN-f) in response to viral infection (12). This evidence concerns the gene IFNE and viral infectious disease.