1. Watanabe N, et al. Autoxidation of extracellular hydroquinones is a causative event for the cytotoxicity of menadione and DMNQ in A549-S cells. Arch Biochem Biophys. 2003 Mar 1;411(1):145-57. 2. Shi MM, et al. Quinone-induced oxidative stress elevates glutathione and induces gamma-glutamylcysteine synthetase activity in rat lung epithelial L2 cells. J Biol Chem. 1994 Oct 21;269(42):26512-7.