Sudden donor changes bring a number of challenges, which it is crucial to deal with quickly. Speaking from the 2018 European Society for Blood and Marrow Transplantation (EBMT) Annual Meeting in Lisbon, Portugal, Angela Leather from the Christie NHS Foundation Trust, Manchester, UK, talks about the unique challenges of sudden donor changes in transplantation, referring to her own personal experience. Patients undergoing chemo- and radiotherapy are severely immunosuppressed, highlighting the importance of donor conformity.