TAG-72 is a large mucin-like glycoprotein that was originally defined by the monoclonal antibody B72.3. TAG-72 is widely distributed in different types of carcinomas. When used in immunohistochemisty, TAG-72 can be used to classify epithelial-derived cancers and in differentiaiting an adenocarcinoma from a mesothelioma. TAG-72 testing is used in gastric cancer patients either undergoing treatment or in remission.
