CD274 and lung cancer: The infiltration of CD3+ TILs correlated positively with the PD-L1 H-score of tumor cells in the primary lung cancer (Spearman ρ = 0.545, P = 0.083; Additional file 3: Figure S3A), and BM (Spearman ρ = 0.444, P = 0.049; Additional file 3: Figure S3B).