While Liu et al49 and Stevens et al44 found IL-10 to be increased in patients with CRSwNP compared to controls, Lucas et al found IL-10 was higher in controls.50 Similarly, Kim et al51 and Lin et al52 found IL-33 to be increased in patients with CRSwNP compared to controls, while Ozturan et al found the opposite.32 When comparing CRSwNP patients with CRSsNP, IL-17A and interferon gamma (IFN-γ) were found to be increased by Chen et al,53 but the reverse was found by Kim et al.54 Here, IL17A is linked to chronic rhinosinusitis without nasal polyps.