IFNG and allergic disease: NOs is stimulated by Th1 cytokines such as interferon-gamma (IFN)-γ and interleukin (IL)-1 which play important roles in intracellular defense against microorganisms while arginase is activated by Th2 related cytokines such as IL-4, IL-5, and IL-13 which are responsible for allergic reactions (7, 8).