HGF promotes lung tissue repair through the inhibition of apoptosis of lung epithelial and endothelial cells, and by counteracting a number of pro-apoptotic and pulmonary fibrosis factors such as TGF-β, IL-1β, IL-8, TNF-α, the basic fibroblastic factor, the insulin-like growth factor, and the platelet-derived growth factor37–46. This evidence concerns the gene TNF and pulmonary fibrosis.