IFNG and hypersensitivity reaction disease: These observations are consistent with our earlier work showing that intrapulmonary administration of IL-18 with an allergen in mice promotes allergic sensitization and Th2 phenotype, and IFN-γ induction by IL-18 has short-term inhibitory effects on allergic inflammation that disappears by three weeks of administration, whereas the Th2 effects become dominant after three weeks and are long lasting [38].