Clara cells secrete large amounts of CC10 (also known as CCSP, CC16, secretoglobin, and uteroglobin) which is increased in bronchoalveolar lavage fluid (BALF) and serum during acute injury such as smoke inhalation or application of pneumotoxicants (naphthalene, 4-ipomeanol (4-IM), chloroethylene), but decreased in chronic or dysplastic airway dysfunction (asthma, chronic obstructive pulmonary disease, or bronchopulmonary dysplasia (BPD) [25,29,63,65]. The gene discussed is SCGB1A1; the disease is bronchopulmonary dysplasia.