1. Department of Biochemistry, School of Life Sciences, University of KwaZulu-Natal (Westville Campus), Durban 4000, South Africa
2. Department of Diabetology & Endocrinology, Kanazawa Medical University, Kahoku-gun, Ishikawa 920-0293, Japan
3. Laboratory of Biology and Pathology of the Endocrine Pancreas, University of Paris-Diderot and CNRS, 75013 Paris, France