SY 38 represents an excellent marker for several neuroendocrine, neuronal and adrenal tumors. Neuronal and adrenal tumors such as pheochromocytomas, paragangliomas, neuroblastomas, ganglioneuroblastomas. Neuroendocrine tumors of epithelial origin: Pancreatic islet cell carcinoma, bronchial and gastrointestinal carcinoids, medullary carcinoma of thyroid. Polypeptide reacting: Mr 38 000 transmembrane glycoprotein of presynaptic vesicles.Reactivity on cultured cell lines: Rat PC-12.