Major positive mediators of lung fibrosis
| Mediator | Cellular response |
| CCL2 | Mediates fibrocyte recruitment and promotes collagen synthesis via TGF-β |
| CCL3 | Mediates fibrocyte recruitment |
| CCL7 | Regulation of collagen synthesis |
| CTGF | Fibroblast mitogen and differentiation; promotes TGF-β-dependent ECM synthesis |
| CXCL12 | Fibrocyte recruitment |
| ET-1 | Fibroblast mitogen and chemoattractant, regulation of ECM synthesis and contraction; promotes EMT |
| FGF2 | Fibroblast mitogen |
| IGF-1 | Fibroblast mitogen and promotes collagen synthesis |
| IL-4 | Regulation of collagen synthesis |
| IL-6 | Regulator of α-SMA expression in myofibroblasts |
| IL-12 | Regulation of collagen synthesis |
| IL-13 | Induction of TGF-β |
| IL-17 | Fibroblast proliferation |
| PDGF | Fibroblast mitogen and chemoattractant |
| TGF-β | ECM production, fibroblast proliferation and differentiation; promotes EMT |
| Thrombin | ECM production, fibroblast proliferation and differentiation |
CCL: CC motif chemokine ligand; CTGF: connective tissue growth factor; CXCL12: CXC motif chemokine ligand 12; ET: endothelin; FGF: fibroblast growth factor; IGF: insulin-like growth factor; IL: interleukin; PDGF: platelet-derived growth factor; TGF: transforming growth factor; ECM: extracellular matrix; EMT: epithelial–mesenchymal transition; α-SMA: α-smooth-muscle actin.