tumor-associated glycoprotein 72 tumor-associated glycoprotein 72 tumor-associated glycoprotein 72 (tag-72) is a glycoprotein found on the surface of many cancer cells, including ovary, breast, colon, lung, and pancreatic cancers. it is a mucin-like molecule with a molar mass of over 1000 kda. tag-72 is a tumor marker measured with radioimmunoassays like ca 72-4, which uses the monoclonal antibodies indium (111in) satumomab pendetide and iodine (125i) minretumomab. this assay has a good specificity for gastric cancer, with a correlation to the neoplasia's extension. it is used to identify relapses of the disease and to follow up the treatment. tag-72 is also the target of the anti-cancer drugs anatumomab mafenatox and minretumomab.