More importantly, several PD-related proteins, such as Parkin, SNCA, DJ-1, LRRK2, UCHL-1, PINK1, vacuolar protein sorting 35 (VPS35), and HtrA2, participate in the regulation of mitochondrial homeostasis, and their mutants lead to mitochondrial impairment. This evidence concerns the gene PRKN and Parkinson disease.