By using a mouse emphysema model, by which emphysematous changes occurred after six months of exposure to CS (but not at one month), it was observed that the BALF cCCN1 level was increased in samples collected from mice after six months of CS exposure but not from those after one month, showing that CCN1 levels correlated with the development of emphysema [230]. The gene discussed is CCN1; the disease is pulmonary emphysema.