Used as a biochemical tool in research to inhibit dihydropyrimidine dehydrogenase (DPD), an enzyme involved in the metabolism of pyrimidines. By inhibiting DPD, it enhances the effectiveness and duration of certain chemotherapy drugs, particularly 5-fluorouracil (5-FU), by preventing their breakdown in the body. This allows for lower doses of 5-FU to be used while maintaining therapeutic efficacy, reducing side effects. It is primarily used in experimental and preclinical cancer studies to modulate drug response and improve treatment outcomes.