Keratin 15 protects against cigarette smoke-induced epithelial mesenchymal transformation by MMP-9.

"Declarations Ethics approval and consent to participateAll animal experiments were approved by the Animal Care and Use Committee of Zhongshan Hospital, Fudan University (No.2022-032). Competing interestsThe authors report no conflicts of interest in this work. Competing interests The authors report no conflicts of interest in this work."

"Funding This work was supported by National Key Research and Development Program of China (2022YFA0806200), National Natural Science Foundation of China (82070045, 82270040, 82170088), Shanghai Municipal Science and Technology Major Project (ZD2021CY001), Shanghai Municipal Key Clinical Specialty (shslczdzk02201), Science and Technology Commission of Shanghai Municipality (20DZ2254400, 20DZ2261200, 21DZ2200600), Natural Science Foundation of Shanghai (20Z11901004), Shanghai Jinshan Municipal Health Commission (GWV-10.1-XK26, JSZK2019A01), Science and Technology Development Fund of Shanghai Pudong New Area (PK2021- Y35), Shanghai Pudong Hospital and the Discipline Construction Promoting Project of Shanghai Pudong Hospital (Zdzk2020 11), and Project of Shanghai Pudong Hospital (RHJJ2017-03)."