First, to the best of the authors' knowledge, this is the first study to reveal that FGF4 can alleviate high-glucose-induced lung injury; Second, it identified a new molecular mechanism by which FGF4 promotes mitophagy to mitigate high glucose-mediated lung damage; Third, it was found that FGF4 can ameliorate lung injury, particularly pulmonary fibrosis (another original observation). This evidence concerns the gene FGF4 and pulmonary fibrosis.