SNCB and Lewy body dementia: β-synuclein (βS), the non-amyloidogenic homolog of αS, is abundantly expressed in the brain, co-localized with αS in the presynaptic terminal.34 Although wild type βS negatively regulates αS aggregation,34 βS containing in dementia with Lewy bodies (DLB)-linked familial mutations P123H and V70M are prone to aggregate and co-promote the aggregation of αS,35,36 leading to neurotoxicity.