SNCA and Parkinson disease: Parkinson's disease (PD) is the fastest-growing neurodegenerative disorder worldwide.1 PD patients show a massive loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and the presence of α-synuclein-rich aggregates (i.e. Lewy bodies) in the surviving cells, culminating in the well-described motor symptoms.2 Despite its heterogeneity, alterations in essential cellular processes, such as mitochondrial dysfunction, oxidative stress, calcium dysregulation, impaired autophagy and mitophagy, protein misfolding and apoptosis, are commonly observed in PD.2