PRKN and Parkinson disease: The selective localization of the lesion in parkin disease is reminiscent of the localization of the lesion in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism.26 Parkin is a protein with the function of mitochondrial quality control,3 and MPTP is a mitochondrial toxin.27 The extent to which the nigral selectivity in MPTP-related disease reflects this mitochondrial selectivity or reflects selective uptake of the MPTP metabolite 1-methyl-4-phenylpyridinium (MPP+) into dopaminergic neurons28 is deserving of further study.