Notably, we observed that the percentages of IFN-γ–producing CD8+ PD-1+ T cells in circulation were significantly higher than those in CD8+ PD-1− T cells in healthy controls (P < 0.001; Figure 1A) and in patients with NSCLC (P < 0.001; Figure 1B). Here, PDCD1 is linked to non-small cell lung carcinoma.