In an attempt to correlate mitochondrial dysfunction as an etiology of autism with gut leakiness [73], induced toxicity was reported to increase the activity of Cytochrome P450-2E1 (CYP2E1) and inducible nitric oxide synthase (iNOS) [74], whereas toxicants suppress the mitochondrial electron transport chain, leading to the elevated production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), resulting in increased oxidative/nitrative (nitroxidative) stress with production of potently toxic peroxynitrite that can nitrate Tyr residues and/or S-nitrosylate Cys residues. Here, NOS2 is linked to autism.