aPaediatric Endocrinology Section, University Children’s Hospital, Tübingen, Germany;
bMedical Research Laboratories, Institute of Experimental Clinical Research, Aarhus
University Hospital, Aarhus, Denmark;
cNational Institute for Biological Standards and Control, South Mimms, Potters Bar,
UK;
dUK NEQAS for Peptide Hormones, Department of Clinical Biochemistry, The Royal Infirmary
NHS Trust, Edinburgh, UK;
eCenter for Endocrinology, Metabolism and Molecular Medicine, Department of Medicine,
Northwestern University Medical School, Chicago, Ill., USA