Similarly, TGF-β1 also augmented collagen gel contraction mediated by the fibroblasts isolated from non-smokers (control; 82.0 ± 2.7% vs. TGF-β1; 78.8 ± 2.7%; P < 0.01) or patients with COPD (control; 79.0 ± 2.8% vs. TGF-β1; 70.1 ± 4.0%, P < 0.01) (Fig. 3b). The gene discussed is TGFB1; the disease is chronic obstructive pulmonary disease.