TYMS and neoplasm: The sensitization mechanism of 5‐fluorouracil is to inhibit the thymidylate synthetase.7 For platinum, its mechanism includes radiation‐induced free radicals prompting the formation of toxic platinum intermediates, inhibition of DNA repair, radiation‐induced enhancement of cell platinum absorption, and cell cycle arrest.8, 9 Via redistributing tumor cells into S phase and causing the depletion of the deoxy ATP, gemcitabine can enhance the radio‐sensitivity of tumor radiotherapy.10 However, these drugs have not only limited sensitization effect, but also overlapped toxicity.