CD8A and chronic obstructive pulmonary disease: To investigate changes in CD8+ T cell subsets in COPD patients, we analyzed the following subsets of T cells in the blood: CD3+CD8+IFN-γ+ (Tc1), CD3+CD8+IL-4+ (Tc2), CD3+CD8+IL-17A+ (Tc17), CD3+CD8+Foxp3+ (CD8+ Tregs), CD3+CD8+IL-10+ (Tc10) and CD3+CD8+α7+ (CD8+α7+) (Figs. 2 and 3).