In response to viral challenge, IPS-1−/− mice developed a type-2 inflammatory response as indicated by a significant eosinophilia and lymphoplasia (Fig. 5b), together with increased production of IL-5 (Fig. 5c) and IL-13 (Fig. 5d) in bronchoalveolar lavage fluid (BALF). This evidence concerns the gene IL5 and Increased total eosinophil count.