PD is generally characterized by two major hallmarks: (1) selective loss of dopaminergic (DA) neurons in substantia nigra pars compacta (SNpc), the region of the brain implicated in movement and muscle contraction control, and (2) the accumulation of misfolded, aggregated alpha-synuclein (α-SYN) fibrils within neuronal somas called Lewy bodies (LBs) or dendrites and axons as Lewy neurites (LNs) [91]. The gene discussed is SNCA; the disease is Parkinson disease.