This gene encodes a type II transmembrane protein that belongs to the interferon-induced transmembrane (IFITM) protein superfamily. The encoded protein functions as a cell surface hyaluronidase that cleaves extracellular high molecular weight hyaluronan into intermediate size fragments before internalization and degradation in the lysosome. It also has an interferon-mediated antiviral function in humans through activation of the JAK STAT signaling pathway. The activation of this gene by transcription factor SOX4 in breast cancer cells has been shown to mediate the pathological effects of SOX4 on cancer progression. Naturally occurring mutations in this gene are associated with autosomal recessive non-syndromic hearing loss. [provided by RefSeq, Mar 2017].