By contrast, MPO expression has been localized to astrocytes in the vicinity of dopamine neurons in PD midbrain samples and in a PD mouse model based on the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; Choi et al. 2005; Chung et al. 2010). The gene discussed is MPO; the disease is Parkinson disease.