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.