Anti-Claudin 9 antibodies are used for the immunodetection of the protein encoded by the CLDN9 gene. In humans, the canonical protein has a reported length of 217 amino acid residues and a mass of 22.8 kDa. Its subcellular localization is in the cell membrane. It is reported to be expressed in the liver, in peripheral blood mononuclear cells and hepatocarcinoma cell lines. A member of the Claudin protein family, it is known to play an important role in tight junction-specific obliteration of the intercellular space, through calcium-independent cell-adhesion activity. The gene encoding this protein is implicated in Deafness. Other names for this target antigen include DFNB116. Gene orthologs have been identified in the mouse, rat, bovine and chimpanzee species.