Epithelial CD8+ lymphocyte numbers were higher in the COPD group (2.72; 0.00-5.69, p = 0.001) compared to the never-smoking controls (0; 0.99-2.01), but without a significant difference compared to smokers with normal lung function (1.34; 0.00-4.71). Here, CD8A is linked to chronic obstructive pulmonary disease.