Previous studies in both animals and humans have shown that CS induces the production of proinflammatory cytokines such as IL-6, IL-8 and TNF-α, as well as ICAM-1, ROS and GSH, which amplify the inflammatory process and play integral roles in the coordination and persistence of inflammationin airway remodelling of COPD patients [29, 30]. Here, CXCL8 is linked to chronic obstructive pulmonary disease.