CXCL8 and respiratory system disorder: It has been reported that disruption of the redox balance by CS leads to the production of proinflammatory cytokines, i.e., IL-1β, IL-6, IL-8, and TNFα in smokers, regulation of which is closely associated with the progression of respiratory diseases, such as COPD (Zuo et al. 2014; Strzelak et al. 2018).