Infection of mice with Nippostrongylus brasiliensis triggers a host protective immune response characterised by increased production of Th2 cytokines IL-13 and IL-4 [27], [28], [29], goblet cell hyperplasia [30] eosinophilia [31] and elevated levels of serum IgG1 and IgE [28], [32]. The gene discussed is IL4; the disease is infection.