*2.1. Chemicals*

Conoidin A, an inhibitor of 2-cystein PRDX1-5 peroxidase activities was purchased from Cayman Chemical (Ann Arbor, MI, USA). MJ33 (1-Hexadecyl-3-(trifluoroethyl)-sn-glycero-2-phosphomethanol lithium), competitive inhibitor of the phospholipase A2 activity of PRDX6 was from Sigma-Aldrich (Milwaukee, WI, USA). Ezatiostat, a glutathione analog inhibitor of the Glutathione S-transferase P1 (GSTP1), required for the re-activation of the peroxidase activity of PRDX6, but not other PRDXs, was

purchased from Sigma-Aldrich (Milwaukee, WI, USA). All-trans-retinoic acid, H2O2 and common reagents were from Sigma-Aldrich (Milwaukee, WI, USA).
