The 35 amino acid fragment found in the plaques was determined to be extremely hydrophobic [7], and multiple lines of evidence indicated that α-synuclein aids the aggregation of Aβ42 in vitro and might be involved in the formation of Aβ plaques in the brains of patients with AD and dementia with Lewy bodies (DLB) [8]. This evidence concerns the gene SNCA and Lewy body dementia.