Cytokine release syndrome (CRS) has been a prominent issue for CAR T-cell therapy. Here, Michel Sadelain, MD, PhD, of the Memorial Sloan Kettering Cancer Center, New York, NY, explains how CRS was first identified, its biology and its current management, while still calling for novel interventions to prevent its occurrence. This video was recorded at the European Society for Medical Oncology (ESMO) 2018 Congress, in Munich, Germany.