MAPT and Parkinson disease: Neurodegenerative disorders like Alzheimer's and Parkinson's diseases are a growing medical problem in modern society.1 Although the molecular mechanism that leads to a propagation of these diseases is not well-understood, it has been established that the misfolding and aggregation of proteins such as β-amyloid and tau in Alzheimer's disease and α-synuclein in Parkinson's disease play a key role in the initiation and spread of the disease.