TS-IN-6 (Compound 10) is a thymidylate synthase (TS) inhibitor with an IC50 value of 0.54 μM, showing significant antiproliferative activity. It can induce G1 phase cell cycle arrest and apoptosis (with notable increases in early and late apoptosis rates) and is useful for research in cancers such as colon, breast, and liver cancer.