Light micrograph showing human gingiva (blue, left) attached by the dark blue coloured band of the junctional epithelium to the enamel (brown) surface of a tooth. The JE extends from the gingival margin to the enamel-cementum junction. The JE is located at the strategically important interface between the gingival sulcus, populated with bacteria, and the periodontal soft and connective tissues that need protection from exposure to bacteria and their products. Its unique structural and functional adaptation enables the junctional epithelium to control the constant microbiological challenge. Magnification: x75 when printed at 10 centimetres tall.