This gene encodes a weak acid-active hyaluronidase. The encoded protein is similar in structure to other more active hyaluronidases. Hyaluronidases degrade hyaluronan, one of the major glycosaminoglycans of the extracellular matrix. Hyaluronan and fragments of hyaluronan are thought to be involved in cell proliferation, migration and differentiation. Although it was previously thought to be a lysosomal hyaluronidase that is active at a pH below 4, the encoded protein is likely a GPI-anchored cell surface protein. This hyaluronidase serves as a receptor for the oncogenic virus Jaagsiekte sheep retrovirus. The gene is one of several related genes in a region of chromosome 3p21.3 associated with tumor suppression. This gene encodes two alternatively spliced transcript variants which differ only in the 5' UTR.