Calciumfolinat fremmer TS- hæmningen, ved at øge det intracellulære folatlager, og dermed stabilisere 5- FU – TS- komplekset og øge aktiviteten.] >
5-FU inhibits thymidylate synthase (TS), a key enzyme involved in pyrimidine biosynthesis, and calcium folinate enhances TS inhibition by increasing the intracellular folate pool, thus stabilising the 5FU-TS complex and increasing activity.]