This gene encodes one of the proteins of the highly conserved urothelium-specific integral membrane proteins of the asymmetric unit membrane which forms urothelium apical plaques in mammals. The asymmetric unit membrane is believed to strengthen the urothelium by preventing cell rupture during bladder distention. The encoded protein is expressed in the peripheral blood of bladder cancer patients with transitional cell carcinomas.[provided by RefSeq, Sep 2009].