In this study, we assessed two coding polymorphisms, rs4925 (Ala140Asp) in GSTO1 and rs156697 (Asn142Asp) in GSTO2 in a large LOAD series of > 8,000 subjects, ~3,000 of whom were older (> 80 years) and in a PD series of > 1,300 subjects including both familial and sporadic cases. The gene discussed is GSTO2; the disease is Parkinson disease.