Cell-free systems using mitochondria isolated from normal and cancer cells [4,7,16,17] have been adopted to study mitochondrial changes upon antagonizing Bcl-2 anti-apoptotic members, which would serve as a promising tool closely imitating the intracellular initiation of MOMP and apoptotic core machinery to verify BH3 mimetics discovered by other assays. The gene discussed is BCL2; the disease is cancer.