Figure 1.

Pan-keratin immunostaining of normal tissues. The panels show a strong pan-keratin positivity of epithelial cells of the stomach (A), the urothelium of the urinary bladder (B), and the squamous epithelium of the oral cavity (C). In the pancreas, acinar cells show a strong staining while cells of islets of Langerhans stain only weakly (D). In the liver pan-keratin staining is variable (weak to moderate) in hepatocytes but strong in bile ducts (E). In the adrenal gland, only a subset of cortical cells shows a weak staining (F). In the myometrium, groups of spindle-shaped pan-keratin positive cells are found (G). In lymph nodes, a delicate fibrillar staining caused by fibroblastic reticulum cells occurs mainly in the interfollicular area (H).