The common pathological feature of neurodegenerative diseases is the collection of pathogenic proteins, such as amyloid β (Aβ) and microtubule-associated protein (MAPT; tau) in AD, α-synuclein in Parkinson’s Disease (PD), TAR DNA-binding protein-43 (TDP-43) and fused in sarcoma (FUS) in amyotrophic lateral sclerosis (ALS). The gene discussed is MAPT; the disease is Parkinson disease.