Apart from IFN-a/b, cytokines such as IFN-c (type II IFN) and IFN-l (type III IFN) exhibit antiviral activities, although they bind to distinct receptors. In particular, type III IFNs induce transcriptional activation of antiviral genes similar to those activated by type I IFN. Type III IFNs act primarily on epithelial cells [11] and probably play an important role in the innate immune response of epithelial tissues to virus infections [12, 13] .