Second, not only environmental factors such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and rotenone but also familial genes such as SNCA (PARK1), Parkin (PARK2) and DJ-1 (PARK7) lead to PD pathogenesis partially by inducing overwhelming ROS production6–8. The gene discussed is SNCA; the disease is Parkinson disease.