Moreover, the quantification of total collagen deposition (Fig. 1d), α-SMA (Fig. 1e), collagen I (Fig. 1f), collagen III (Fig. 1g) and vimentin (Fig. 1h) positive area per small airway revealed a significant increase of those fibrosis markers in CS-exposed mice as compared to air-exposed animals. The gene discussed is ACTA1; the disease is fibrosis.