PRKN and Parkinson disease: Among the heterogenous PD-associated genes that have been identified from the familial PD research, two candidate genes PINK1 (encoding PINK1, PTEN-induced serine/threonine kinase 1) and PRKN (encoding Parkin, E3 ubiquitin ligase), associated with early onset PD26,27; and proteins their encode are characterized to play an essential role in maintaining mitochondrial function, monitoring mitochondrial damage and initiating mitophagy10,11,28–30.