Chronic rhinosinusitis (CRS) with nasal polyps is characterized by a T helper (Th) 2 cells-dominated inflammation with upregulation of IL-4, IL-5, and IL-13 and an increase in eosinophil count, ECP, and immunoglobulin E. CRS without nasal polyps is characterized by Th1-dominated inflammation with upregulation of IL-2, TGF-beta, and IFN-gamma. This evidence concerns the gene IL5 and nasal cavity polyp.