One patient with overt disease prior to CAR infusion relapsed with CD19+ disease 90 days after treatment, and all patients showed signs of normal CD19+ B-cell recovery, highlighting that CAR T-cells in these patients did not persist indefinitely in contrast to those in the aforementioned CLL trial that harbored the 4-1BB costimulatory domain. The gene discussed is CD19; the disease is B-cell chronic lymphocytic leukemia.