There are multiple mechanisms involved in the anti-cancer effects of shikonin, including ER stress, ROS generation, glutathione (GSH) depletion, mitochondrial membrane potential disruption, p53, superoxide dismutase (SOD) and Bax up-regulation, PARP cleavage, catalase and Bcl-2 down-regulation [591, 612–614]. This evidence concerns the gene BCL2 and cancer.