PRKN and Parkinson disease: The priming of damaged and/or dysfunctional mitochondria for autophagic degradation requires the engagement of two gene-encoding proteins that are mutated and functionally defective in early-onset recessive Parkinson’s disease—the phosphatase and tensin homologue (PTEN)-induced putative kinase 1 (PINK1), which encodes for a mitochondrially localized kinase, and PARK2, with a protein product, Parkin, that is a cytosolic E3 ubiquitin ligase [20,26].