{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Cytokeratin 7 (CK7) reacts with proteins that are found in most ductal, glandular and transitional epithelium of the urinary tract and bile duct epithelial cells. CK7 distinguishes between lung and breast epithelium that stain positive, and colon and prostate epithelial cells that are negative."}]},{"type":"paragraph","children":[{"type":"text","value":"This antibody also reacts with many benign and malignant epithelial lesions (e.g., Adenocarcinomas of the ovary, breast and lung). Further, in frozen sections, the antibody has been shown to label the rete epithelium in the testis, epididymis epithelium, and the surface epithelium of the stomach and duodenum. Transitional-cell Carcinomas are positive and Prostate Cancers are negative. This antibody does not recognize intermediate filament proteins, nor does it recognize non-epithelial tissues such as blood vessels, connective tissue, etc."}]}]}