To clarify the effect of the cytokines during viral infection in ECRS patients, we investigated the production of thymic stromal lymphopoietin (TSLP) in the sinus mucosa of ECRS patients in the presence of polyinosinic: polycytidylic acid, or poly(I:C), which mimics viral infection, with or without interleukin-4 (IL-4) or IL-13. Here, TSLP is linked to viral infectious disease.