Serum CC-16 levels decrease in different chronic lung diseases, such as chronic pulmonary obstructive lung disease (COPD) (6, 7), asthma (8), and chronic exposure to different toxic agents (9–12), whereas higher CC-16 levels were noticed in patients with sarcoidosis (5, 13), pulmonary fibrosis (14), and acute exposure to smoke and toxic agents (15, 16). The gene discussed is SCGB1A1; the disease is chronic obstructive pulmonary disease.