Rong B, Fu T, Gao W, et al. - Researchers performed this study among patients with stable chronic obstructive pulmonary disease (COPD), to determine the correlations between serum level of Clara cell secretory protein (CC16) and clinical parameters in these patients. For this purpose, they used linear correlation analysis and multiple linear regression analysis. ELISA was used to ascertain the serum concentration of CC16. Downregulation of serum level of CC16 was detected in stable COPD patients vs healthy control group. A negative link of reduced serum CC16 with smoking, GOLD grading, mMRC score and medical history of patients, but its positive correlation to pulmonary function, was revealed. CC16 level was influenced by smoking, FEV1/FVC values, COPD grading, and mMRC scores. Serum CC16 yielded a sensitivity of 65.3% and a specificity of 75% for identifying COPD. Overall, findings revealed a correlation of reduced serum level of CC16 with disease progression of COPD, indicating that it can serve as an indicator contributing to the diagnosis and evaluation of COPD.