Anti-upp antibodies enable researchers to detect and measure the upp antigen in biological samples. This target is a reported synonym of the UPP1 gene, which encodes uridine phosphorylase 1. This protein is known to function in carbohydrate metabolism and homeostasis, among other biological roles. The human version of upp has a canonical amino acid length of 310 residues and a protein mass of 33.9 kilodaltons, although 2 isoforms have been identified. It is reported to be notably expressed in the small intestine, oral mucosa, esophagus, duodenum, and appendix. upp is a member of the PNP/UDP phosphorylase protein family. ELISA and Western Blot are common applications for upp antibodies.