More CD8+ T cells in tumor stroma were presented in NSCLC with COPD comparing with NSCLC without COPD patients, and contrary, more CD8+ T cells in tumor islets were found in NSCLC patients without COPD compared to NSCLC patients with COPD (P < 0.05) (Table 3). Here, CD8A is linked to chronic obstructive pulmonary disease.