Anti-UPIa antibodies are used in antigen-specific immunodetection in biological samples. The target UPIa is a known alias name of the protein uroplakin 1A, encoded by the UPK1A gene in humans. This 258-amino acid residue protein is a known component of the asymmetric unit membrane (AUM); a highly specialized biomembrane elaborated by terminally differentiated urothelial cells. It is localized to the membrane of the cell and features glycosylated post-translational modifications. It is reported to be expressed in the urinary bladder. Other synonyms for UPIa include TSPAN21 and UP1A.