The differential gene expression pattern indicated altered activity of upstream mediators that regulate pathways involved in regeneration (HGF) and remodeling (TGF-β1), but also apoptosis (p53), vascularization (PDGF-BB, endothelin 1) and inflammation (IFNs), which are all relevant to COPD pathophysiology. Here, TGFB1 is linked to chronic obstructive pulmonary disease.