MPO and colorectal carcinoma: Numerous studies have reported increased levels of phospholipase A2 (PLA2) and myeloperoxidase (MPO) enzymes, associated with the production of high concentrations of free radicals, including RNS and ROS as well as increased levels of MDA and 4-HNE, major products of lipid peroxidation in patients with CRC [87–89].