Ghorashian et al. [111] designed a novel CD19 CAR (CAT) with a lower affinity but more robust cytotoxicity than FMC63, which showed a high CR rate (12/14, 86%) with a low toxicity rate (no severe CRS; 1 severe ICANS) in the treatment of R/R pediatric B-ALL. Here, CD19 is linked to precursor B-cell acute lymphoblastic leukemia.