In addition to the classic nigrostriatal α-synuclein misfolding and dopaminergic neuronal loss, several mechanisms contribute to the brain changes described in PD, including synaptic dysfunction and loss, mitochondrial dysfunction, retrograde signaling impairment, and altered neurotransmitter activity, among others (Aarsland et al., 2017). The gene discussed is SNCA; the disease is Parkinson disease.