IFNB1 and viral infectious disease: Thus, while NF-κB is activated by virus infection and does associate with the ifnβ enhancer, it does not appear to be required for subsequent transcription of ifnβ. These findings raise two key questions: (1) what is the function of the NF-κB site in the ifnβ promoter, and (2) what is the function of NF-κB in virus-triggered innate immune responses, if not to activate ifnβ?