Thymidylate synthase has been recognized as a rate‐limiting enzyme in de novo pyrimidine biosynthesis and plays a key role in the metabolism of folate and deoxythymidine for DNA synthesis and repair.25, 26 Several studies reported that the TS‐expression level is related to the therapeutic performance in clinical cases for the treatment of gastric cancer; the higher the TS expression, the poorer the therapeutic performance.27, 28 Hence, TS is considered a critical target for the treatment of malignantly advanced gastric cancer. This evidence concerns the gene TYMS and gastric cancer.