At the 2016 Annual Meeting of the Europea n Society for Blood and Marrow Transplantation (EBMT), held in Valencia, Spain, Catherine Bollard, MD, from Children’s National Health System, Washington, D.C., provides an overview of the toxicities, including cytokine release syndrome that correlates with both toxicity and efficacy, which can be observed in patients with acute lymphoblastic leukemia (ALL) who are undergoing chimeric antigen receptor (CAR) T-cell therapy.