Glutathione is such a critical soldier in our line of defense that our bodies make it themselves. We even have mechanisms that recycle and reuse it. But what happens when our toxic Selenium as an Antioxidant: Roles and Clinical Applications in Critically Ill and Trauma Patients: A Narrative Review Selenium containing 15 Mer Peptides with High Glutathione Peroxidase like Activity ScienceDirect Characterization and structural analysis of human selenium dependent glutathione peroxidase 4 mutant expressed in Escherichia coli ScienceDirect