Anti-hyaluronidase 4 antibodies are used for the immunodetection of the protein encoded by the HYAL4 gene. In humans, the canonical protein has a reported length of 481 amino acid residues and a mass of 54.2 kDa. Its subcellular localization is in the membrane. It is notably expressed in the placenta and skeletal muscle. A member of the Glycosyl hydrolase 56 protein family, it is a reported endo-hyaluronidase that degrades hyaluronan to smaller oligosaccharide fragments. Post-translational modifications have been described, including glycosylation. Other names for this target antigen include chondroitin sulfate endo-beta-N-acetylgalactosaminidase, chondroitin sulfate hydrolase, hyaluronoglucosaminidase 4, and CSHY. Gene orthologs have been identified in the mouse, rat, bovine, frog and chicken species.