CMTM4 and gastric neoplasm: Additionally, CMTM6 has three special traits in gastric adenocarcinoma: (1) CMTM6 localizes not only on the membrane of tumor epithelium, but also in cells in the mesenchymal region; (2) CMTM6 protein expression level is positively correlated with tumor burden or more metastatic sites; and (3) CMTM6 co-expresses with CMTM4 on the gastric tumor epithelial cells and mesenchymal cells.