They enhance the induction of protective immunity (both T helper type 1 (Th1)- and Th2-type responses) against influenza infection when they are coadministered with vaccines; in MC-deficient mice, this protection is significantly reduced.22 In mice, IL-18 administration results in MC-mediated recruitment of DCs and T cells to the sites of inflammation.23 This suggests that IL-18 and IL-33 activate MCs to ensure effective development of antiviral immune responses. This evidence concerns the gene IL18 and influenza.