CXCL8 and chronic obstructive pulmonary disease: Higher gene expression levels of IL-8 and MCP-1 were found in the bronchiolar epithelium of subjects with COPD (de Boer et al., 2000) and increased levels of IL-8 in sputum and BALF of patients with COPD compared with healthy smokers (Keatings et al., 1996; Tanino et al., 2002).