Core B – Summary Core B of Human and Mouse Liver Surgery will be responsible for patient consent, human sample collection and screening, as well as conducting microsurgery procedures related to mouse models of hepatic IRI and OLT for all three projects in this PPG. The specific aims are as follows: Aim 1. To collect, process, and store human biological samples from OLT patients. Donor liver biopsy tissue and peri-, intra- and post-operative blood and fluid samples from the operative field and blood samples peripherally will be collected. Processing and storage will be centralized. Analysis by request from individual projects will be performed. Core B will also collect and maintain the database with all relevant patient data for the PPG duration. Aim 2. To provide OLT and local liver IRI murine microsurgeries and post-operative care in mice with quality and consistency. The Core will be responsible for conducting all the microsurgical OLT/non-transplant procedures and post- transplant care in mice in all three projects. These procedures are technically demanding, and the Core will assure consistent and reliable surgical outcomes in conducting experiments, as proposed in this PPG. Aim 3. To coordinate experiments among projects and maximize the use of biological samples from human OLT patients and mouse liver transplants/recipients. The Core will coordinate experiments between projects to i/ maximize the use of clinical samples from transplanted patients, and ii/ minimize the numbers and costs of experimental animals for microsurgeries. Aim 4. To store extra-human/mouse biological samples and maintain the archive. The Core will store and record surplus tissue samples (liver grafts, host tissues, serum) and maintain them as an archive for potential future use. Aim 5. To offer other surgical support. Based on the experience, and available equipment, Core B will provide support for additional surgical procedures in mouse liver IRI models, such as i.v., and portal vein injections. Core B will enable collaborating PIs of all three projects to achieve their goals by providing skilled technical and scientific expertise and guidance in the key areas of human and liver transplantation surgery, critical to the successful performance of the PPG.