Impairment of UPS has already been reported in patients with familial PD, namely with mutations in genes linked to quality control mechanisms, such as parkin and ubiquitin C-terminal hydrolase-L1 (Kitada et al., 1998; Leroy et al., 1998; Dawson and Dawson, 2003; Martin et al., 2011). This evidence concerns the gene PRKN and Parkinson disease.