MAPT and Parkinson disease: Alpha-synuclein accumulates in a group of neurodegenerative diseases collectively known as synucleinopathies with PD being the most common, while the accumulation of tau is a defining feature of tauopathies classically found in the brains of patients with Alzheimer’s disease (AD) or progressive supranuclear palsy (PSP) (Dugger and Dickson, 2017).