The accumulation of the presynaptic neuronal protein α-synuclein (α-syn), can activate UPR signaling through PERK in dopaminergic neurons in the brain of PD patients [111,112,113], whereas GSK2606414 inhibition of PERK demonstrates neuroprotective capacity in a PD mouse model and prevents neuronal death in Parkin mutant flies [114,115]. Here, PRKN is linked to Parkinson disease.