SNCA and Parkinson disease: Owing to its proposed key role, α-synuclein is one of the most compelling targets for the development of disease-modifying therapies targeting synucleinopathies.20-22 Immunotherapy with monoclonal antibodies targeting extracellular α-synuclein may prevent pathological spreading of α-synuclein, slowing the progression of Parkinson’s disease, multiple system atrophy and other synucleinopathies.23,24 Pre-clinical models in mice have shown that passive immunization is effective at removing pathological α-synuclein and improving related deficits.20-22