This antibody recognizes a protein of 38kDa, identified as synaptophysin. It labels normal neuroendocrine cells of human adrenal medulla, carotid body, skin, pituitary gland, thyroid, lung, pancreas, gastrointestinal mucosa, Paneth cells in the gastrointestinal tract and of gastric parietal cells. Neurons in the brain, spinal cord, and retina are also labeled. In combination with anti-chromogranin A and anti-NSE, Ab to synaptophysin is very useful in the identification of normal neuroendocrine cells and neuroendocrine neoplasms