It is known that enhanced ROS production could trigger apoptosis by disrupting the mitochondrial membrane, phenomena observed during our ultrastructural analysis; immunocytochemical staining indeed confirmed the activation of caspase-3 in CDDP- and Pt(IV)Ac-POA-treated samples as well as a significant downregulation of COX2, especially in mesothelioma cells. Here, PTGS2 is linked to mesothelioma.