Efforts to build this link between PINK1/Parkin-PD and iPD have traditionally focused on the use of fibroblasts or induced pluripotent stem cells (iPSCs) from PINK1 and PRKN mutation carriers and iPD cases to study the effects of these proteins on mitophagy in endogenous, human model systems [69,70,71]. Here, PRKN is linked to Parkinson disease.