NT5C3B (5'-Nucleotidase, Cytosolic IIIB) is a Protein Coding gene. The NT5C3B gene, located on 17q21.2, is conserved in chimpanzee, Rhesus monkey, dog, cow, mouse, rat, chicken, fruit fly, mosquito, A.thaliana, rice, and frog. NT5C3B specifically hydrolyzes 7-methylguanosine monophosphate (m(7)GMP) to 7-methylguanosine and inorganic phosphate. The specific activity for m(7)GMP may protect cells against undesired salvage of m(7)GMP and its incorporation into nucleic acids. Also has a weak activity for CMP. UMP and purine nucleotides are poor substrates. NT5C3B is widely expressed in the testis, thyroid, and other tissues. Among its related pathways are Metabolism and Gene Expression. 215 organisms have orthologs with human gene NT5C3B.