These cells are active and more mature since 30 % of CD4+ and CD8+ T lymphocytes co-expressed the nuclear p65 NF-κB subunit in the bronchial biopsies of COPD patients [27], and in patients with stable COPD, BAL CD8+CD45RA+ and lower CD8+CD45R0+ number are seen than in smokers with normal lung function [31]. Here, CD8A is linked to chronic obstructive pulmonary disease.