CDKN1B and chronic obstructive pulmonary disease: Overexpressed CDKN1B partially countervailed the suppressive influence of miR-221-3p on cell apoptosis and inflammatory response in CSE-treated 16HBE cells, indicating that CDKN1B is a positive regulator in COPD and is involved in miR-221-3p-medaited COPD pathogenesis.