AREG and Airway obstruction: Analysis of 1199 genes revealed that 107 were involved in various respiratory tract-related diseases (i.e., obstructive lung diseases, respiratory hypersensitivity, bronchogenic carcinoma, asthma, pulmonary fibrosis and chronic obstructive pulmonary disease), and twelve genes (Ace2, Acta2, Adipoq, Areg, Cat, Cfd, Col3a1, Eln, Fn1, Il12b, Sod1, and Wnt5a) were involved in pulmonary fibrosis (Table 2).