UCK2 Inhibitor-3 is a non-competitive inhibitor targeting uridine-cytidine kinase 2 (UCK2), a key enzyme in the pyrimidine salvage pathway, with an IC50 value of 16.6 μM. Notably, UCK2 can partially substitute for dihydroorotate dehydrogenase (DHODH) in infected or rapidly dividing cells, facilitating effective uridine salvage. Furthermore, UCK2 Inhibitor-3 exhibits inhibition of DNA polymerase eta and kappa, with IC50 values of 56 μM and 16 μM, respectively.