PARK7 and Parkinson disease: Parkinson’s disease (PD) is characterized by an impairment in the mitochondrial respiratory Complex I activity, leading to altered Ca2+ homeostasis and ROS generation, by the presence of mtDNA mutations, and by mutations in many of the genes involved in the removal of the damaged organelles through the mitophagy process, such as Parkin, PINK1, LRKK2, DJ-1.