Recently, elevated pleural IL-33 and ILC2s were found to mediate the induction of asthma-like responses (e.g., AHR, production of Th2 cytokines) following pdmH1N1 infection in Rag1−/− mice (on a C57Bl/6 background) that lack functional T and B lymphocytes (196). Here, AHR is linked to infection.