Frontiers Evidence that protein thiols are not primary targets of intracellular reactive oxygen species in growing Escherichia coli The glutathione peroxidase Gpx4 prevents lipid peroxidation and ferroptosis to sustain Treg cell activation and suppression of antitumor immunity: Cell Reports Fluorescence turn on assay for glutathione reductase activity based on a conjugated polyelectrolyte with multiple carboxylate groups Journal of Materials Chemistry (RSC Publishing) DOI:10.1039 C0JM02400G Glutathione reductase Sigma Aldrich