Daniel Couriel, MD, MS, University of Utah, Salt Lake City, UT, gives a summary of his talk at EBMT 2021 on reducing therapy-related toxicity in graft-versus-host disease (GvHD). Prof. Couriel discusses the challenges of measuring whether toxicity has been successfully reduced in GvHD. Prof. Couriel also talks about the reduced toxicity of novel therapies and the value of non-relapsed mortality as an indirect measure of reduced toxicity. This interview took place during the 47th Annual Meeting of the European Group for Blood and Marrow Transplantation (EBMT) 2021.