Graft-versus-host disease (GVHD) is the most serious and challenging complication of allogeneic haematopoietic stem-cell transplantation (HSCT). There is a need for developing new approaches to mitigate GVHD and ultimately facilitate the use of allogeneic HSCT for the treatment of haematological cancers. In this Review, the authors discuss rationale, clinical evidence, and outcomes of the current GVHD prophylaxis and assess the clinical evidence for emerging approaches in the prevention of GVHD.
