NOS2 and airway hyperresponsiveness: The disease is driven primarily by Th2 lymphocyte-mediated inflammation and is characterized by pulmonary eosinophilia, Th2 cytokines and allergen-specific IgE production, mucus hypersecretion, expression of inflammatory factors such as inducible nitric oxide synthase (iNOS), and airway hyperresponsiveness (AHR) [2, 3].