1 August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark. Electronic address: erichter@nexs.ku.dk.
2 Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia.
3 Pennington Biomedical Research Center, Baton Rouge, LA, USA.
4 Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.