IFNAR1 and viral infectious disease: Consistently, cell-intrinsic IFNAR signaling in DCs is required in many circumstances for the induction of protective immunity, including efficient CD8 T cell responses during viral infection or tumor development (96–98), Th1 responses upon PolyI:C injection independently of IL-12 or IFN-γ effects (99, 100), as well as follicular helper T cell and humoral responses (101, 102).