Altered interleukin levels in animals with pulmonary fibrosis could impact their weight, survival rate, etc. As an anti-inflammatory and anti-fibrotic cytokine, IL-10 inhibits the downregulation of IFN-γ and upregulation of TGF-β1 in bleomycin-induced pulmonary fibrosis mice, thereby reducing the number of infiltrated inflammatory cells and development of lung fibrosis. This evidence concerns the gene IL10 and pulmonary fibrosis.