Specifically, while catalase can protect cells from tumor initiation and progression [31, 32, 33, 34] due to its role in preventing the accumulation of dangerous levels of oxidants, many cancer cells require high oxidant detoxifying systems and upregulation of catalase for tumor progression and metastasis to compensate for high ROS production and prevent the action of cell death processes [15, 35, 36, 37, 38]. This evidence concerns the gene CAT and cancer.