Review ArticleEvolution of Quality Assurance for Clinical Immunohistochemistry in the Era of Precision Medicine – Part 2: Immunohistochemistry Test Performance CharacteristicsTorlakovic, Emina E. MD, PhD*†‡; Cheung, Carol C. MD, PhD, JD*§; D’Arrigo, Corrado MB, ChB, PhD, FRCPath∥¶#; Dietel, Manfred MD, PhD**; Francis, Glenn D. MBBS, FRCPA, MBA, FFSc (RCPA)††,‡‡,§§; Gilks, C. Blake MD∥∥; Hall, Jacqueline A. PhD¶¶; Hornick, Jason L. MD, PhD##; Ibrahim, Merdol PhD***; Marchetti, Antonio MD, PhD†††; Miller, Keith FIBMS***; van Krieken, J. Han MD, PhD‡‡‡; Nielsen, Soren BMS§§§,∥∥∥; Swanson, Paul E. MD¶¶¶; Vyberg, Mogens MD§§§,∥∥∥; Zhou, Xiaoge MD###,****; Taylor, Clive R. MD††††; From the International Society for Immunohistochemistry and Molecular Morphology (ISIMM) and International Quality Network for Pathology (IQN Path)Author Information *Department of Laboratory Medicine and Pathobiology, University of Toronto, Vancouver, BC, Canada Department of †Laboratory Hematology §Pathology, University Health Network, Toronto, ON, Canada ‡Canadian Immunohistochemistry Quality Control (CIQC)/Canadian Association of Pathologists National Standards Committee for High Complexit Testing/Immunohistochemistry ∥Poundbury Cancer Institute ¶Dorset County Hospital NHS Foundation Trust #Cancer Diagnostic Quality Assurance Services (CADQAScic), Dorchester, UK ***UK National External Quality Assessment Scheme (UK NEQAS), University College London, London, UK **“Rudolf-Virchow-Haus”, Institute of Pathology, Charité—University Hospital Berlin, Berlin, Germany ††School of Medicine, Griffith University, Gold Coast ‡‡Genomics For Life, Brisbane, QLD §§RCPA Quality Assurance Program, Sydney, NSW, Australia ∥∥Vancouver General Hospital, University of British Columbia, Vancouver, BC, Canada ¶¶International Quality Network for Pathology (IQN Path), Luxembourg City, Luxembourg, and Division of Cancer, Department of Surgery & Cancer, Imperial College London, UK ##Brigham and Women’s Hospital, Harvard Medical School, Boston, MA †††Center of Predictive Molecular Medicine, Center for Excellence on Ageing and Translational Medicine, University of Chieti-Pescara, Chieti, Italy ‡‡‡Department of Pathology, Radboud University Medical Centre, Nijmegen, The Netherlands §§§Institute of Pathology, Aalborg University Hospital and Department of Clinical Medicine, Aalborg University, Denmark ∥∥∥Nordic Immunohistochemistry Quality Control (NordiQC), Aalborg, Denmark ¶¶¶Department of Pathology and Laboratory Medicine, Cumming School of Medicine, University of Calgary and Calgary Laboratory Services, Calgary, AB ###Department of Pathology, Beijing Friendship Hospital, Capital Medical University ****CCP-IHCQC, Chinese Committee for Pathologists—Immunohistochemistry Quality Control, Beijing, China ††††Keck School of Medicine, University of Southern California, Los Angeles, CA The authors declare no conflict of interest. Reprints: Emina E. Torlakovic, MD, PhD, Department of Laboratory Hematology, Toronto General Hospital/UHN, 200 Elizabeth Street, Toronto, ON, Canada M5G 2C4 (e-mail: email@example.com). Applied Immunohistochemistry & Molecular Morphology: February 2017 - Volume 25 - Issue 2 - p 79-85 doi: 10.1097/PAI.0000000000000444 Buy Metrics Abstract All laboratory tests have test performance characteristics (TPCs), whether or not they are explicitly known to the laboratorian or the pathologist. TPCs are thus also an integral characteristic of immunohistochemistry (IHC) tests and other in situ, cell-based molecular assays such as DNA or RNA in situ hybridization or aptamer-based testing. Because of their descriptive, in situ, cell-based nature, IHC tests have a limited repertoire of appropriate TPCs. Although only a few TPCs are relevant to IHC, proper selection of informative TPCs is nonetheless essential for the development of and adherence to appropriate quality assurance measures in the IHC laboratory. This paper describes the TPCs that are relevant to IHC testing and emphasizes the role of TPCs in the validation of IHC tests. This is part 2 of the 4-part series “Evolution of Quality Assurance for Clinical Immunohistochemistry in the Era of Precision Medicine.” Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.