Cluster of differentiation (CD) 4+ and CD8+ T-cells of the T-helper type 1 (Th1) or T-cytotoxic type 1 (Tc1), respectively, are central in the systemic inflammation in COPD and for the immune responses to those pathogens that are frequently found in COPD subjects [4,5]. Here, CD8A is linked to chronic obstructive pulmonary disease.