However, there were no significant differences in the activation of CD8+ T-lymphocytes between ex-smokers (24.1%, 4.7–48.4) and healthy smokers (52.3%, 27.2–72.8; p>0.05) or current smokers with COPD (34.3%, 13.8–56.2; p>0.05). Here, CD8A is linked to chronic obstructive pulmonary disease.