In neurons, α‐synuclein normally participates in the regulation of neurotransmitter release from the presynaptic terminals.5 Mutations and multiplications in SNCA cause familial PD.3 Recently, genomewide association studies have consistently identified common genetic variants close to the SNCA locus that increase the risk for idiopathic PD.6, 7 A large body of evidence suggests that the accumulation of α‐synuclein plays a key role in PD. Here, SNCA is linked to Parkinson disease.