To confirm that BEX2 and CD274 are mutually exclusive in their expression, we tested BEX2 and CD274 protein expression by western blot or flow cytometry using 16 cell lines derived from various cancers, including cholangiocarcinoma, hepatocellular carcinoma, gastric cancer, lung cancer, and glioma. The gene discussed is BEX2; the disease is hepatocellular carcinoma.