Here, we showed two important results supporting the α-syn toxicity to pancreatic function: (1) α-syn deposited in the pancreatic islets of T1DM diabetic mice to a greater extent compared to non-diabetic mice (Additional file 1: Fig. S4); (2) the insulin content in the BAC mouse pancreas reduced significantly compared to WT mice (Fig. 2a, b). Here, INS is linked to type 1 diabetes mellitus.