However, during infection with LCMV or MCMV, IL-33 promotes the expansion of NK cells and T cells and their production of IFN-γ, and loss of the IL-33R results in a delay in viral clearance (Nabekura et al., 2015; Bonilla et al., 2012; Baumann et al., 2015). Here, IL1RL1 is linked to infection.