Uroplakin-3A (UPK3A) is a component of the asymmetric unit membrane (AUM). It is a highly specialized bio-membrane made by terminally differentiated urothelial cells. The protein may play an important role in AUM-cytoskeleton interaction in terminally differentiated urothelial cells. UPK3A also contributes to the formation of urothelial glycocalyx, which may play an important role in preventing bacterial adherence through FimH bacterial protein binding leading to bladder infection. UPK3A has been shown as a helpful marker for the detection of bladder cancer.