iNOS, myeloperoxidase (MPO), NADPH oxidase, and xanthine oxidase (XO), as well as upregulated cyclooxygenase 2 (COX2) and lipoxygenase (LOX), are just a few of the oxidant-producing enzymes that the inflammatory cells in the tumor microenvironment activate [363,364,365]. This evidence concerns the gene PTGS2 and neoplasm.