Smoking increased the expression of IL-33 in lung epithelial cells, enhances the response to virus infection, inhibits ST2 expression in ILC2s, increases ST2 expression in NK cells and macrophages, and aggravates the disease, with increased expression of TNF-α, IL-12, and IFN-γ observed in mice that were sensitized via smoking and re-infected with the virus [167]. This evidence concerns the gene IL33 and viral infectious disease.