Bouche C, Lopez X, Fleischman A, Cypess AM, O\textquoterightShea S, Stefanovski D, Bergman RN, Rogatsky E, Stein DT, Kahn R, et al. Insulin enhances glucose-stimulated insulin secretion in healthy humans. Proceedings of the National Academy of Sciences. 2010;107(10):4770–4775.