The function of ENSG00000143179 (UCK2, uridine-cytidine kinase 2) is as follows. Phosphorylates uridine and cytidine to uridine monophosphate and cytidine monophosphate (PubMed:11306702, PubMed:11494055, PubMed:35583288). Does not phosphorylate deoxyribonucleosides or purine ribonucleosides (PubMed:11306702). Can use ATP or GTP as a phosphate donor (PubMed:11306702). Can also phosphorylate cytidine and uridine nucleoside analogs such as 6-azauridine, 5-fluorouridine, 4- thiouridine, 5-bromouridine, N(4)-acetylcytidine, N(4)-benzoylcytidine, 5-fluorocytidine, 2-thiocytidine, 5-methylcytidine, and N(4)- anisoylcytidine (PubMed:11306702). {ECO:0000269|PubMed:11306702, ECO:0000269|PubMed:11494055, ECO:0000269|PubMed:35583288}.