TRPC1 and chronic obstructive pulmonary disease: There are 7 TRPC subfamily isoforms (TRPC1-TRPC7) that could be activated by a variety of inflammatory cytokines and membrane stretch stimulus.[14] It was reported that there was abundant TRPC1 protein expression in airway epithelial cells, showing an obvious increase of patients with chronic airway inflammatory disease compared with the normal patients.[15] Thus, this study explored the impact of TRPC1 on EMT occurrence in airway epithelial cells of COPD patients with the least expectation to provide a theoretical basis for the study of COPD mechanism.