Here we demonstrate that cisplatin/LA-12 and TRAIL combination-induced cytotoxicity was associated with profound stimulation of the mitochondrial apoptotic pathway in several human prostate cancer cell lines, as evidenced by the enhanced cleavage of Bid, activation of Bak, drop of mitochondrial membrane potential, and caspase-9 activation. The gene discussed is CASP9; the disease is prostate carcinoma.