IFNK and viral infectious disease: Our data for the first time reveals that IFN family members respond differently to the same stimulation in keratinocytes, and IFNκ is the dominant type of IFNs in keratinocytes under unstimulated and stimulated conditions of itself, poly (I:C), and HSV-1 in both undifferentiated and differentiated conditions, suggesting that IFNκ may be the dominant IFN of skin host defense against viral infections.