Martinez-Valbuena et al. (2018) demonstrated the increased accumulation of phosphorylated α-synuclein and IAPP in the pancreatic β cells of the patients who suffered from different synucleinopathies, including PD, DLB, and incidental Lewy body disease. However, no correlative changes α-synuclein aggregation in the brain were described (Martinez-Valbuena et al., 2018). This evidence concerns the gene SNCA and Lewy body dementia.