Antioxidant functions for the hemoglobin β93 cysteine residue in erythrocytes and in the vascular compartment in vivo

► The conserved hemoglobin β93Cys modulates reactions between red cells and H2O2. ► β93Cys-deficient mice are more susceptible to endotoxemia-related injury. ► β93Cys may affect inflammatory stress via modulation of H2O2 metabolism.