NF-H is an abundant, stable cytoplasmic protein located in neuronal cells in large axons frequently used as a cell type marker. The NF-H protein shares a high degree of structural and sequence homology with the NF-L and NF-M subunits, especially in the coiled-coil core domain. NF-M and NF-H form flexible extensions linking the neurofilament proteins to each other and other cytoplasmic proteins. Deletions and insertions in the NF-H protein have been reported in amyotrophic lateral sclerosis. The NF-01 monoclonal antibody reacts with a conserved phosphorylated epitope of NF-H present in all species and has been reported to be useful for Western blotting, immunohistochemistry using formalin-fixed, paraffin-embedded tissues and immunofluorescence staining.