PINK1 and Parkinson disease: Although multiple mechanisms have been suggested to be involved in the regulation of mitophagy,6, 7, 8, 9 the PTEN-induced putative kinase 1 (PINK1)/PARK2 pathway is the best characterized and most extensively studied signaling mechanism of mitophagy, partly due to the recognized significance of these two molecules in the pathogenesis of Parkinson's disease.10, 11, 12 In healthy non-depolarized mitochondria, the serine/threonine kinase PINK1 is constantly and rapidly turned over by mitochondrial proteases.