There were decreased levels of HGF in response to TGF-β stimulation in lung fibroblasts from healthy subjects at normoxic (p = 0.011) and hypoxic conditions (p = 0.0027), and in COPD patients at normoxic (p = 0.0027) and hypoxic (p = 0.009) conditions (Fig. 3c). This evidence concerns the gene HGF and chronic obstructive pulmonary disease.