The bone marrow microenvironment contains cellular niches that maintain the pool of hematopoietic stem cells while supporting hematopoietic maturation. Furthermore, hematological malignancies co-opt normal cellular interactions in order to promote their own growth and evade therapy. In vivo systems to study human hematopoiesis have mostly been achieved through xenotransplantation into immunodeficient mouse models. However, incomplete cross-compatibility between the murine stroma and transplanted human hematopoietic cells limit the rate of engraftment and the study of relevant interactions. Recently, several groups have reported as an alternative strategy the use of three-dimensional human bone marrow organoids in vivo and in vitro, generated from bone marrow stromal cells seeded onto osteoinductive scaffolds. In this ISEH New Investigator webinar, we will hear from two experts in this field: Dr. Dominique Bonnet from the Francis Crick Institute and Dr. Paul Bourgine from Lund University. We hope you can join us!