Previous work by us and others have shown that alpha-Synuclein (αSyn), the major aggregating protein that forms insoluble fibrils found in Lewy bodies in diseases such as Parkinson's disease (PD) and dementia with Lewy bodies, is expressed also in pancreatic β-cells9–11 and that αSyn levels are increased in β-cells of mice lacking the T2D associated gene Ide10 and in islets from T2D patients10,11. Here, SNCA is linked to Parkinson disease.