Abstract
Using antisera raised against defatted human cream we have demonstrated a new antigen on the epithelial membrane. An indirect immunoperoxidase technique on routinely processed histological sections was used, and we describe results which show that this antigen has a widespread but highly selective distribution, being apparently localised to membranes that have a secretory function. The antigen is carried by a variety of adenocarcinomas, suggesting that its localisation may have a role in the diagnosis and differential diagnosis of malignant disease.