Although IFN-γ–dependent PD-L1 upregulation on tumor cells was thought to mediate the suppression on intratumor CD8+ T cells in certain tumors (8), recent studies have suggested PD-L1 expression was more frequently detected on immune cells than on malignant cells in HCC, non–small cell lung cancer, urothelial carcinoma, and esophageal squamous cell carcinoma (13–15). This evidence concerns the gene IFNG and lung cancer.