PDCD1 and non-small cell lung carcinoma: As shown in Supplementary Figure S2A, the densities of CD8+ cells and FOXP3+ Treg cells in NSCLC tissue were significantly positively correlated (r = 0.3691, p <0.0001), and the densities of CD8+ T cells and FOXP3+ Treg cells were positively correlated with PD-1 expression (r = 0.7234, p <0.0001 and r = 0.4684, p <0.0001, respectively) (Supplementary Figures S2B, C).