CD14 and chronic obstructive pulmonary disease: The number of EVs expressing CD14 (a macrophage marker) was significantly higher in both smokers with COPD [610 (200–900) events/μL; p < 0.001] and those without COPD [360 (70–590) events/μL; p = 0.007] than in non-smokers [190 (110–298) events/μL].