Ever since platelet transfusions were shown to reduce mortality from haemorrhage in patients with acute leukaemia in the 1950s, the use of this therapy has steadily grown to become an essential part of the treatment of cancer, haematological malignancies, marrow failure, and haematopoietic stem cell transplantation. Today, more than 1·5 million platelet products are transfused in the USA each year, 2·9 million products in Europe. However, platelet transfusion can transmit infections and trigger Join discussion...