1. Paediatric Research Centre, University of Tampere Medical School and Tampere University Hospital, Tampere, Finland.
2. Department of Developmental Biology, University of Tampere Medical School, and Department of Pathology, Tampere University Hospital, Tampere, Finland.
3. Institute of Medical Technology, University of Tampere, Tampere, Finland, and Department of Biology of Physical Activity, University of Jyväskylä, Jyväskylä, Finland.