1 Department of Haematology, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK. Electronic address: suepavord@doctors.org.uk.
2 Department of Haematology, University College London Hospitals NHS Foundation Trust and Cardiometabolic Programme-NIHR UCLH/UC BRC, London, UK.
3 Department of Haematology, University Hospitals Birmingham, Birmingham, UK.
4 Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK.
5 Thrombosis & Haemophilia Centre, Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK.