PRKN and neurodegenerative disease: It is noteworthy that prevalent neurodegenerative diseases in humans, such as Alzheimer’s, Parkinson’s, and ALS, are accompanied by aberrant mitophagy and/or impaired mitophagy flux [12] and this is paralleled by a reduced presence of specific markers, such as PINK1, Parkin, phosphoglycerate mutase 5 (PGAM5), and other already-mentioned mitophagy-associated proteins (MAPs), in the plasma from patients with several types of dementia, cognitive impairment or neurodegenerative diseases, reflecting a significant downregulation of this pathway in these pathological conditions [13,17] (Figure 1).