GPC3 and gastric cancer: By contrast, metastatic gastric cancer may display variable CK7, CK 20, and CDX2 expression.17,18) Although the gastric tumor was CK7-positive and the intestinal lesions were CK7-negative, previous studies have reported such discrepancies between primary gastric cancers and their metastases.19) Additional immunohistochemical staining (Hepatocyte, Arginase-1, and Glypican-3) was negative, effectively excluding hepatocellular carcinoma as the origin.