Tumor cells protect themselves by activating an antioxidant system that involves glutathione (GT), glutathione peroxidase (GPx), glutathione S-transferase (GST), glutaredoxin (Grx), thioredoxin (Trx), superoxide dismutase (SOD), and catalase (CAT) [20,21,22]. This evidence concerns the gene GLRX and neoplasm.