SOD2 and Parkinson disease: In a study using MPTP (1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine), 3-nitropropionic acid (3-NP), and malonate to induce PD symptoms in mice, Andreassen et al. found that heterozygous MnSOD knockout mice have greater dopamine depletion and larger striatal lesions compared to wildtype mice [401].