Apoptosis inducer 18, a potent inducer of apoptosis , shows significant cytotoxicity to the breast cancer cell line MCF-7 ( IC 50 =0.559 μM). Apoptosis inducer 18 inhibits cell cycle progression and promotes apoptosis by binding to DNA and causing damage, and by binding to the active site of CDK-2 , interfering with its kinase activity. Apoptosis inducer 18 can be used in anti-breast cancer research.