Damaged gallbladder tissue. Coloured scanning electron micrograph (SEM) of epithelial tissue and cells forming the lining of the gallbladder. This tissue is damaged, with some of the cells dying (brown) in process called apoptosis. This degeneration may be caused by a range of conditions, such as cancer (carcinoma) or gallstones. The gallbladder stores bile produced in the liver, and releases it to aid in the digestion of fats. Magnification: x2500 when printed at 10 centimetres across.