Anti-H2AP antibodies are used in the immunodetection of the protein H2A.P histone. In humans, the canonical protein has a reported length of 117 amino acid residues and a mass of 13.4 kDa. It is notably expressed in the testis. Synonyms for this target antigen include HIP17, HYPM, huntingtin-interacting protein M, histone H2A.P, huntingtin interacting protein M, and CXorf27. H2AP gene orthologs have been reported in the mouse, rat and chimpanzee species.