FGFR1 and chronic obstructive pulmonary disease: Second, our study suggests that cigarette smoke exposure caused the loss of FGFR1 expression and impairment of FGFR1 signaling, and that FGF10 attenuates cigarette smoke-induced COPD through FGFR1 signaling; further confirmatory studies, including the use of FGFR1 knockout mice, are necessary to fully elucidate the precise associated mechanisms.