The main pathological hallmarks of PD are a slow and progressive loss of dopaminergic (DAergic) neurons in the substantia nigra pars compacta (SNpc), causing decreased synaptic outflow of DA in the striatum, and accumulation of misfolded neuronal α-synuclein inclusions, known as Lewy bodies (LBs) and Lewy neurites (LNs)4–6. The gene discussed is SNCA; the disease is Parkinson disease.