CXCL8 and chronic obstructive pulmonary disease: Ex and current smoking participants with COPD had significantly more OSM detected (p = 0.036), significantly higher gene expression of TLR2 (p = 0.019), IL-8 (p = 0.030) and OSM (p = 0.028), and significantly higher levels of IL-8 (p<0.001), NE (p = 0.013) and higher levels of MMP-9 (p = 0.13) compared to healthy ex and current smokers.