Follow-up care for cancer patients is necessary to evaluate the effectiveness of the treatment they receive. Here, Arnon Nagler, MD, from Chaim Sheba Medical Center, Tel-Aviv, Israel, describes the numerous predictive factors that are currently being used to evaluate the response towards CAR T-cell therapy. This video was recorded at the 1st European CAR T-Cell Meeting, held in Paris, France, co-organized by the European Society for Blood & Marrow Transplantation (EBMT) and the European Hematology Association (EHA).