In the interaction of human-derived fibroblasts (FEF3) and human esophageal squamous cell carcinoma cells (TE4 or TE8), activation with both CM-TE4 and CM-TE8 also significantly increased PD-L1 expression in FEF3 (Fig. 3C, D). This evidence concerns the gene CD274 and esophageal squamous cell carcinoma.