Many clinically important neurodegenerative diseases are associated with amyloids, e.g., Alzheimer’s disease (AD) with β-amyloid and Tau amyloid; Parkinson’s disease (PD) and dementia with Lewy bodies (DLB) with α-synuclein amyloids; and tauopathies, including Pick’s disease, with Tau amyloids. The gene discussed is SNCA; the disease is Parkinson disease.