PROJECT SUMMARY We propose to organize and conduct the Eleventh (11th) Annual Pediatric Transplant and Cellular Therapy Consortium (PTCTC) Meeting at the Seattle Convention Center, which is an indoor arena located in Seattle, WA, on April 2, 2024. A unique aspect of the Annual PTCTC Educational Meeting is that it is jointly held with the international American Society of Pediatric Hematology Oncology Conference (April 3-6, 2024) and includes a Combined Plenary Session, bringing pediatric hematology oncology professionals together from around the world. Hematopoietic cell transplantation (HCT) is a potentially curative therapy for many childhood illnesses. Basic, translational, and clinical research advances have significantly increased non-relapse mortality after HCT. The remarkable success is partly owed to the presentation, dissemination, and sharing of new knowledge at annual meetings. This 1-day program will invigorate the field of pediatric HCT. The theme of the 11th Annual PTCTC Educational Meeting will be “The First 100 Days”. The meeting will focus on transplant-related complications and improving care during the first 100 days after HCT. Sessions focusing on transplant complications will include presentations and discussions on endothelial injury (e.g., veno-occlusive disease and thrombotic microangiopathy), infections, and acute graft versus host disease. The fourth session will be a dedicated session analyzing the first 100 days from a patient's and parent’s perspective; the speakers will include a transplant survivor and his dad. Finally, we will have a session dedicated to healthcare provider burnout. The primary objectives include providing evidence-based guidelines to screen, recognize, and treat endothelial injury after HCT through standardized strategies that can be implemented irrespective of the treating institution; II) review the “state of the science” in acute GVHD immunology and management; III) provide clinically relevant strategies to preserve the microbiome, and decrease infections after HCT; IV) enhance the understanding of wellness, thereby maximizing long-term quality-of-life and survivorship of pediatric HCT patients and their parents; V) review physician burnout and provide attendees meaningful strategies to recognize and prevent burnout; VI) provide mechanisms to recognized to promote networking and collaboration of research and clinical trials involving pediatric HCT patients. The results of the 11th Annual PTCTC Educational Meeting will likely enhance our understanding of the basic, translational, and clinical state of the scientific research in the first 100 days after HCT, which will provide an opportunity and platform to engage young and senior clinicians and scientists to develop collaborative research. The Organizing Committee will make every effort to enhance diversity by increasing individuals from diverse backgrounds, including those from underrepresented groups. Participation of trainees and underreprese...