Synucleins are small soluble proteins expressed primarily in neural tissues and in certain tumors. The family includes 3 known proteins, alpha synuclein, beta synuclein and gamma synuclein. All synucleins have in common a highly conserved alpha helical lipid binding motif with similarity to the class A2 lipid binding domains of the exchangeable apolipoproteins. The alpha and beta synuclein proteins are found primarily in brain tissue, where they are seen mainly in pre synaptic terminals. Alpha synuclein is believed to be a major component of Lewy bodies in Parkinson’s disease. Mutations in alpha synuclein are associated with rare familial cases of early onset Parkinson’s disease, Alzheimer’s disease and several other neurodegenerative illnesses.