IL33 and chronic rhinosinusitis without nasal polyps: To test the hypothesis that viral infection would induce IL-25, IL-33, and TSLP release in epithelia derived from CRSwNP patients, but not CRSsNP patients, we measured the production of TSLP, IL-25, and IL-33 by epithelial cells derived from nasal polyps of CRSwNP, in vitro exposed to poly(I:C), a synthetic analog of viral dsRNAi, compared to epithelial cells derived from sinus mucosa of CRSsNP.