IFNK and viral infectious disease: IFN-ε is involved in local immune responses against viruses in epithelial tissues and the mucosal surfaces of the lung and reproductive tract; IFN-ζ is expressed by dendritic cells in response to viral infections and cancer, and contributes to the stimulation of T cells; IFN-κ is expressed in keratinocytes and protects the skin against viral infections; IFN-ω is produced in response to viral infections; and IFN-τ plays an important role in pregnancy [50].