Anti-Arkadia antibodies enable researchers to detect and measure the Arkadia antigen in biological samples. This target is a reported synonym of the RNF111 gene, which encodes ring finger protein 111. This protein is known to function in the regulation of transcription and protein ubiquitination, among other biological roles. The human version of Arkadia has a canonical amino acid length of 994 residues and a protein mass of 108.9 kilodaltons, although 4 isoforms have been identified. It is reported to be localized in the nucleus and cytoplasm of cells and widely expressed in many tissue types. Other names for this target antigen include ARK, hRNF111, and E3 ubiquitin-protein ligase Arkadia.