The effects of caryophyllene oxide on the PI3K/AKT/mTOR/S6K1 and MAPK signaling pathways in human prostate (PC-3) and breast (MCF-7) cancer cell lines was found to increase generation of ROS from mitochondria, which induced apoptosis (assessed by annexin V and TUNEL staining), loss of mitochondrial membrane potential, release of cytochrome c, activation of caspase-3, and cleavage of PARP, as well as affecting the expression of several gene products that mediate cell proliferation and metastasis. Here, CASP3 is linked to cancer.