GZMB and chronic obstructive pulmonary disease: The immune checkpoint PD1 of CD8+ MAIT cells was higher in COPD+ NSCLC tissue than in COPD− NSCLC tissue (Figure 2C), whereas the levels of GZMB and IFN‐γ in CD8+ MAIT cells was lower in COPD+ NSCLC tissue than in COPD− NSCLC tissue (Figure 2D).