Mitochondrial release of cytochrome c triggers apoptosis via the assembly of a multimeric complex including caspase-9, Apaf-1, and other components, sometimes called the apoptosome. Library screens have identified small molecules that activate the apoptosome by binding to one or more of its components. CAY10443 is one such molecule. In a cell free, multi-component assay, it activated caspase-3 with an EC50 of 5 µM. These apoptotic activators represent therapeutic lead compounds for the development of antitumor drugs.