The National Institute for Health Research (NIHR) Blood and Transplant Research Unit (BTRU) in Donor Health and Genomics at the University of Cambridge is a cross-disciplinary unit established to address major questions about the health of blood donors and produce evidence-based strategies to enhance donor safety and ensure sustainability of blood supply. The Unit is funded by the NIHR and is a partnership between the University of Cambridge and NHS Blood and Transplant (NHSBT), in collaboration with the University of Oxford and the Wellcome Sanger Institute.