IL17A and chronic rhinosinusitis without nasal polyps: Cytokine profiles, including IL-4, IL-5, IL-13, IL-25, IL-33, TSLP (in CRSwNP) and TGF-β, type I interferons, IL-6, IL-8, or IL-17 (in CRSsNP) in nasal tissue are perhaps the most investigated and promising biomarkers for phenotyping CRS and targeting therapeutically [121].