Enzyme-linked immunosorbent assays demonstrated decreased IL-17A expression upon prolonged exposure to hypoxia in both IT and NP samples from patients with CRSwNP, while IL-17A increased in control IT epithelial cells; correlation and time-dependency were observed between HIF1α and IL-17A expression in both IT and NP samples from patients with CRSwNP. This evidence concerns the gene IL17A and chronic rhinosinusitis with nasal polyps.