1. Institute of Clinical Molecular Biology, University of Kiel, Rosalind-Franklin-Straße 12, 24105 Kiel, Germany.
2. The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, Bruna Stråket 16, 41345 Gothenburg, Sweden.
3. Department of Clinical Physiology, Sahlgrenska University Hospital, Gothenburg, Sweden.
4. Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.