reported that IL-33 released by bleomycin-injured lung epithelial cells induced the release of IL-13 from ILC2, and then promoted the differentiation of macrophage to IL-33 secreting M2, which further lead to the secretion of IL-13 and TGF-β, and promoted the pulmonary fibrosis (22). This evidence concerns the gene IL33 and pulmonary fibrosis.