Austrian Association for Quality Assurance and Standardization of Medical and Diagnostic Tests (ÖQUASTA), UK National External Quality Assessment Scheme (UK NEQAS) for Haematology, University Hospitals Birmingham NHS Foundation Trust, Instituto de Salud Pública de Chile, Centre Toulousain pour le Contrôle de qualité en Biologie clinique (CTCB), Royal College of Pathologists of Australasia Quality Assurance Program, Independent, Leiden University Medical Centre, Sciensano, Laboratoire National de Métrologie et d’Essais (LNE), National Health Institute Doutor Ricardo Jorge (INSA), Reference Institute for Bioanalytics, Medical University of Innsbruck - University Hospital of Innsbruck, LGC, Ltd., University of Szeged, Reference Institute for Bioanalytics, Medical University of Vienna - Vienna General Hospital, External Quality Control for Assays and Tests (ECAT) Foundation, National Health Institute Doutor Ricardo Jorge (INSA), UK National External Quality Assessment Scheme (UK NEQAS) Immunology, Immunochemistry & Allergy (IIA), Careggi University Hospital of Florence, The Norwegian Organization for Quality Improvement of Laboratory Examinations (Noklus), Tirol Kliniken GmbH, Medical University of Vienna - Vienna General Hospital, QMD Services, INSTAND e.V. Society for Promoting Quality Assurance in Medical Laboratories, University of Ulsan - Asan Medical Center, Radboud University - Radboud University Medical Center, Queen Beatrix Regional Hospital, NGO AQALM, Institut für Qualitätssicherung in der Virusdiagnostik - IQVD GmbH, University of British Columbia (UBC) - Department of Pathology and Laboratory Medicine and University of British Columbia (UBC) - Department of Pathology and Laboratory Medicine