CAT and neoplasm: The generation and consumption of H2O2 in tumor cells are maintained in a relatively stable state through a complex redox system, which involves various redox enzymes such as superoxide dismutase (SOD) [13,14,15], catalase (CAT) [16,17,18], peroxidase (POD) [19,20,21], and glutathione peroxidase (GPx) [22,23,24].