CatB-IN-1 is an enzyme inhibitor with significant inhibitory activity against tumor invasion. CatB-IN-1 may reduce the invasiveness of tumor cells by regulating intracellular protein metabolism. CatB-IN-1 demonstrates effective anti-invasive ability in cell models and can significantly reduce the invasive ability of MCF-10A neoT cells. The structure-activity relationship study of CatB-IN-1 shows that its design can target multiple functions of cat hepsin B[1].