Alpha-synuclein is a member of the synuclein family,.The synuclein family members, including α-synuclein and β-synuclein, are predominantly expressed in the brain where they influence synaptic regulation and neuronal plasticity. hyper-phosphorylated forms of α-syn protein are the pathological hallmark of Lewy body disease, which includes Parkinson's disease (PD), diffuse Lewy body disease (DLBD), and Lewy body variant of Alzheimer's disease (LBV).