Further evidence of the important inflammatory state was the number of CD8+ T cells in the alveolar walls that was increased in smokers with COPD [7 (2.5–10) cells/mm] compared to smokers without COPD [3 (1–7) cells/mm, p = 0.0001, Figure 2B] and non-smokers [1.9 (1–4) cells/mm, p < 0.0001; Figures 2C, D]. Here, CD8A is linked to chronic obstructive pulmonary disease.