Next, the cancer cells were pretreated with various ROS scavengers such as N-acetylcysteine (NAC), thiol antioxidant (reduced glutathione, GSH), manganese superoxide dismutase (SOD) mimetic [Mn(III) tetrakis (4-benzoic acid) porphyrin chloride, MnTBAP], and H2O2 scavenger (catalase-polyethylene glycol) before DET, DETD-35, or PTX treatment. This evidence concerns the gene CAT and cancer.