CD19 and precursor B-cell acute lymphoblastic leukemia: To determine whether the observed activities of LoopCAR-1 in B-ALL translate to lymphoma models, we conducted in vitro comparisons and found that, compared with those of CD19 CAR-T cells and LoopCAR-4, LoopCAR-1 exhibited markedly enhanced lymphoma killing and cytokine release activity (Fig. S11A and S11B).