UPP1 and neoplasm: Uridine phosphorylase catalyses the reversible phosphorolysis of uridine to uracil.8, 9 There is an article discovered uridine phosphorylase activity in tumours appeared approximately twofold to threefold higher associated with normal tissues.10 The high expression of Uridine phosphorylase in oral squamous cell carcinoma has been proved as a prognostic marker.11 Uridine phosphorylase has two isoforms in human, UPP1 and UPP2.12, 13 UPP1 is ubiquitously distributed and massively expressed in the human body.