"In short, cytokine storm involves an immune response that causes collateral damage, which may be greater than the immediate benefit of the immune response." Carl H. June, MD, and David C. Fajgenbaum, MD, December 2020 It is a now familiar story - following her third infusion of CAR T cells to treat acute lymphoblastic leukemia, young Emily Whitehead developed pyrexia, respiratory failure, severe hypotension and shock. Shortly thereafter, an expedited blood test revealed a thousand-fold increase in the cytokine IL-6. Fortunately, an IL-6 inhibitor, the monoclonal antibody tocilizumab, had recently been FDA approved to treat systemic juvenile idiopathic rheumatoid arthritis. By luck, Emily's caregivers were aware of this fact because the daughter of team member Carl June, MD, had recently begun taking the drug. Emily is administered tocilizumab, experiences a rapid and complete recovery and is alive today. (Emily's experience and the early history of CAR T therap...