CD274 and neoplasm: In all patients with wild type EGFR tumors, serum PD-L1 levels correlated with tumor PD-L1 level (R = 0.35, p = 0.004; Fig. 2D) and the number of CD8+ TILs (R = 0.26, p = 0.034; Fig. 2E), while tumor PD-L1 levels tended to be correlated with the number of CD8+ TILs (R = 0.21, p = 0.083; Fig. 2F).