Anti-notochord homeobox antibodies are used in the immunodetection of the protein encoded by the NOTO gene. In humans, the canonical protein has a reported length of 251 amino acid residues and a mass of 27 kDa. Its subcellular localization is in the nucleus. The notochord homeobox protein is involved with nervous system development and the regulation of cell differentiation, among other functions. Other names for this target antigen include homeobox protein notochord and notochord homolog.