Antibodies to the 65-kD isoform of glutamic acid decarboxylase (GAD65) are demonstrated to damage the structure and function of pancreatic β cells, which is positively associated with an increased risk of both type 1 and type 2 diabetes mellitus in adults.28,29 Strikingly, the level of GAD65 antibodies in the adult model was extremely significantly elevated compared with that in the adult control; furthermore, there was no significant change in the GAD65 level between the controls, corresponding models, or vaccination groups (Supplementary Fig. 2f). Here, GAD2 is linked to type 2 diabetes mellitus.