Anti-ubiquitin specific peptidase 9, X-linked antibodies are protein reagents that detect specific antigens. The ubiquitin specific peptidase 9, X-linked antigen is another term for the human protein ubiquitin specific peptidase 9 X-linked, encoded by the USP9X gene. The protein is known to function in cell division and cell migration, among other biological roles. Canonically, it has an amino acid length of 2554 residues and a mass of 290.5 kilodaltons. Its subcellular localization is in the cytoplasm and it is found to be widely expressed in embryonic and adult tissues. The ubiquitin specific peptidase 9, X-linked protein is a member of the Peptidase C19 protein family.