Neurofilaments are a type of intermediate filament that serve as major elements of the cytoskeleton supporting the axon cytoplasm. Neurofilaments usually contain three intermediate filament proteins: L, M, and H (68/70, 160, and 200 kDa) which occur in the central and peripheral nervous system and are usually neuron specific. This antibody stains an antigen localized in a number of neural, neuroendocrine, and endocrine tumors, such as neuromas, ganglioneuromas, gangliogliomas, ganglioneuroblastomas and neuroblastomas, paragangliomas, as well as adrenal and extra-adrenal pheochromocytomas. Carcinoids, neuroendocrine carcinomas of the skin, and oat cell carcinomas of the lung also express neurofilament. This antibody specifically recognizes the light neurofilament subunit or NF-L (68 kDa); it is not cross-reactive with other intermediate filament proteins.