Shouval R, Fein JA, Labopin M, et al. - Given that a pivotal change in stem cell transplantation has been the introduction of donors other than HLA-matched siblings, therefore, researchers undertook this retrospective, multicentre study to evaluate the evolution of outcomes within donor groups over time. They also examined if donor–recipient HLA disparity might be beneficial in patients with aggressive disease. Participants were selected from the European Society for Blood and Marrow Transplantation and included adult patients (≥ 18 years) with haematological malignancies who had their first allogeneic hematopoietic stem cell transplantation (HSCT) between Jan 3, 2001, and Dec 31, 2015. This study included 106,188 patients, observed over a median duration of 4·1 years (IQR 1·7–7·7). After allogeneic stem cell transplantation, improved overall survival was achieved, with substantial progress seen among recipients of haploidentical and cord blood HSCT. Nonetheless, the continuation of the traditional donor hierarchy of matched sibling donors followed by matched unrelated donors and then other donors was evident.