Anti-Nucleolar protein 66 antibodies enable researchers to detect and measure the Nucleolar protein 66 antigen in biological samples. This target is a reported synonym of the RIOX1 gene, which encodes ribosomal oxygenase 1. This protein is known to function in chromatin organization and the regulation of transcription, among other biological roles. The human version of Nucleolar protein 66 has a canonical amino acid length of 641 residues and a protein mass of 71.1 kilodaltons, although 2 isoforms have been identified. It is reported to be localized in the nucleus of cells. Nucleolar protein 66 is a member of the ROX protein family.