By William J. Marshall, MA, MSc, PhD, MBBS, FRCP, FRCPath, FRCPEdin, FIBiol, Consultant Clinical Biochemist and Clinical Director of Pathology, The London Clinic; Emeritus Reader in Clinical Biochemistry, Kings College London, London, UK; Márta Lapsley, MB BCh BAO, DipPath, MRCPath, MD, FRCPath , Consultant Chemical Pathologist, Epsom and St. Helier NHS Trust and Clinical Lead for Health Informatics, Epsom and St Helier NHS Trust; Honorary Senior Lecturer in Clinical Endocrinology and Nutrition, Centre for Clinical Science and Measurement, University of Surrey; Honorary Senior Research Fellow, South West Thames Institute for Renal Research and Andrew Day, MA MSc MBBS FRCPath , Consultant Chemical Pathologist, Weston Area Health Trust and University Hospitals Bristol Foundation Trust; Honorary Senior Clinical Lecturer in Chemical Pathology, University of Bristol; Head of Severn Deanery Postgraduate School of Pathology, Bristol, UK