Several proteins relevant to PD and/or glutathione metabolism can be nitrated; these include tyrosine hydroxylase (TH), α-synuclein, superoxide dismutase 1 (Sod1, also known as CuZn), manganese superoxide dismutase, glutathione reductase, glutaredoxin, glutathione-S-transferase and cytochrome c oxidase (reviewed by Szabó et al., 2007; and Danielson and Andersen, 2008). This evidence concerns the gene HPGDS and Parkinson disease.