Despite having demonstrated promising response rates in treated patients, CAR T-cell therapies are faced with regulatory issues. Bruce Levine, PhD, from the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, discusses how the therapy’s reliance on genetic modification, viral production, and cell expansion can pose challenges to the clinical application of CAR T-cells. This video was recorded at the European Society for Blood and Marrow Transplantation (EBMT) 2019 Annual Meeting, held in Frankfurt, Germany.