TRANSPLANT IMMUNOLOGY: REJECTION, TOLERANCE AND HISTOCOMPATIBILITY: Edited by Valeria R. MasProfiling the liver graftCelaj, Stelaa; Levitsky, JoshbAuthor Information aDepartment of Internal Medicine bDivision of Gastroenterology and Hepatology, Comprehensive Transplant Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA Correspondence to Josh Levitsky, MD, MS, Professor of Medicine and Surgery, Division of Gastroenterology and Hepatology, Comprehensive Transplant Center, Northwestern University Feinberg School of Medicine, 676N. St. Clair Street, 19th Floor, Chicago, IL 60611, USA. E-mail: [email protected] Current Opinion in Organ Transplantation: February 2021 - Volume 26 - Issue 1 - p 17-22 doi: 10.1097/MOT.0000000000000834 Buy Metrics Abstract Purpose of review Achieving operational tolerance remains a priority in liver transplantation. Although several biomarkers of tolerance and rejection have been identified, few have been reproducible and validated across centers, and therefore have yet to reach clinical practice. Here we summarize findings from prior seminal studies and review current developments in profiling the liver allograft. Recent findings Substantial efforts and progress have been made in the recent years towards the discovery of reliable biomarkers that can predict and guide successful immunosuppression withdrawal. Recent studies have also investigated the transcriptomic signatures underlying not only acute rejection but also subclinical inflammation and chronic allograft injury. Summary As new genomic and sequencing technologies continue to develop, clinical trials are underway to validate biomarkers of tolerance, as well as better understand the mechanisms of both acute and subclinical rejection, with the goal of maximizing allograft survival. Altogether, this will hopefully enable the implementation of immunosuppression withdrawal protocols into clinical practice and make operational tolerance reliably attainable in the near future. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.