A gloved hand holds a vial labeled DO NOT SHAKE, with laboratory equipment and molecular diagrams blurred in the background. “Don’t Shake the Vial” is emphasized at the top as a key reminder for safe handling.
Diagram illustrating how leucovorin, a vitamin, boosts 5-FU chemotherapy: leucovorin stabilizes the FdUMP-thymidylate synthase complex, inhibiting DNA synthesis and causing cancer cell apoptosis.