However, fibroblasts derived from COPD patients first treated for 48 h with either TGFβ1 or GHK were able to induce full collagen I gel contraction comparable to that observed in fibroblasts from former smokers without COPD (P < 0.01, Figure 6b,c). The gene discussed is TGFB1; the disease is chronic obstructive pulmonary disease.