PARK7 and Parkinson disease: Dysfunction of mitochondrial pathway and oxidative stress are also a focus based on the findings that PD-related neurotoxins such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), 6-hydroxydopamine (6-OHDA), and rotenone could interfere with mitochondrial functions and that monogenic PD gene products DJ-1, PINK1, and Parkin are involved in mitochondrial maintenance and redox regulation.