Some autosomal recessive forms of PD are associated with mutations in PARKIN (PARK2), an E3 ubiquitin ligase that is important for neuronal protein homeostasis (Lücking et al., 2000; Bonifati et al., 2003; Valente et al., 2004; Trempe and Fon, 2013). Here, PRKN is linked to Parkinson disease.