IL5 and chronic rhinosinusitis with nasal polyps: The tissue samples of CRSwNP patients without recurrence, patients who had a first revision surgery for recurrence, and patients who had a second revision surgery for recurrence were examined for the levels of IL-1 beta, IgE, specific IgE, IL-5, interferon (IFN) gamma, IL-6, IL-17, transforming growth factor (TGF) beta1, and myeloperoxidase.