QM31 (SVT016426), a cytoprotective agent, is a selective inhibitor of Apaf-1. QM31 inhibits the formation of the apoptosome (IC50=7.9μM), the caspase activation complex composed by Apaf-1, cytochrome c, dATP and caspase-9. QM31 exerts mitochondrioprotective functions and interferes with the intra-S-phase DNA damage checkpoint[2].In Vitro: SVT016426 (0.5-2 μM) inhibits Apaf1-induced activation of caspase activity with an IC50 of 5 μM in HeLa S100 cells.