SNCA and autosomal dominant cerebellar ataxia: However, further evaluations of disease and target specificity and potential PET signal retention in α-synuclein-positive dementia with Lewy body (DLB) patients versus expected α-synuclein-negative Alzheimer’s disease (AD), progressive supranuclear palsy (PSP), and spinocerebellar ataxia (SCA) patients are still needed.