IFNG and esophageal squamous cell carcinoma: 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).