1. Centre for Endocrinology, Diabetes, and Metabolism (D.A.V., B.A.H., J.W.T., W.A., P.M.S.), University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
2. Oxford Centre for Diabetes, Endocrinology, and Metabolism (T.M.B., M.I.M., J.A.H.W.), University of Oxford, Oxford OX3 7LJ, United Kingdom
3. Institute of Reproductive and Developmental Biology (S.F.), Imperial College London, London W12 0NN, United Kingdom
4. Wellcome Trust Clinical Research Facility (P.N.), University Hospital Birmingham, National Health Service Foundation Trust, Birmingham B15 2PR, United Kingdom