OS curves for different mRNA expression levels of TS, TP, and DPD. Note: OS of (A) TS expression groups, (B) TP expression groups, and (C) DPD expression groups were analyzed using the Kaplan-Meier method. TS, TP, and DPD mRNA expression levels were divided according to median values. Abbreviations: TS, thymidylate synthetase; TP, thymidine phosphorylase; DPD, dihydropyrimidine dehydrogenase.