PINK1 and Parkinson disease: PINK1 is a mitochondrial protein kinase in which loss-of-function mutations are the second most frequent known cause of autosomal recessive Parkinson’s disease.96 This protein regulates the activity of parkin, affects mitochondrial stability and modulates mitophagy; however, several studies have reported evidence for Parkinson’s disease mutations in PINK1 resulting in DA release defects in both animal and human-based models before or without neuronal cell death.