Arnon Nagler, MD, Chaim Sheba Medical Center, Tel-Aviv, Israel, discusses highlights from day one of the COSTEM 2021 meeting, highlighting progress in the haploidentical transplant setting, in the treatment of chronic graft-versus-host disease (GvHD), and in the use of immunotherapies. This interview took place at the 6th Congress on Controversies in Stem Cell Transplantation and Cellular Therapies (COSTEM), which took place virtually.