The pathogenesis of pulmonary fibrosis involves various mediators such as TGF-β, legumain, osteopontin, IL-4, IL-6, IL-13, IL-17, TNF-α, Gal-1, Gal-3, PDGF, and FGFR-1. The gene discussed is TGFB1; the disease is pulmonary fibrosis.