IL17A and chronic rhinosinusitis with nasal polyps: Cases of CRSwNP appear to be associated with a Th1-, Th2-, or Th17-biased inflammatory process, an increase in several pro-inflammatory and inflammatory cytokines, including interleukin 5 (IL-5), IL-13, IL-17A, interferon gamma (IFN-γ), IL-33 and IL-25 [2,3].