To date, RT–QuIC assays have been developing to detect protein seeding activity for prion diseases in animals as well as in humans, α-synuclein in the synucleinopathies such as Parkinson disease (PD), multiple system atrophy (MSA), dementia with Lewy bodies (DLB) as well as tau aggregation in Alzheimer’s disease (AD), chronic trauma to encephalopathy (CTE), Pick disease (PiD). The gene discussed is MAPT; the disease is multiple system atrophy.