The right balance of T-cell expansion needs to be achieved in order to obtain the optimal response to CAR T-cell therapy. To enable this, an increased understanding of the factors that affect the response is required. Here, Tanya Siddiqi, MD, of the City of Hope National Medical Center, Duarte, CA, discusses her presentation on what pre-infusion patient characteristics and biomarkers were found to affect response in the TRANSCEND-NHL-001 trial (NCT02631044) of the anti-CD19 CAR T-cell product JCAR017 for aggressive B-cell non-Hodgkin lymphoma (NHL). This video was recorded at the American Society of Hematology (ASH) 2017 Annual Meeting and Exposition in Atlanta, GA.