A Phase I/II single-institutional study of tisagenlecleucel in thirty children and young adults with CD19+ R/R B-ALL (NCT01626495) showed a high remission rate of 90% at 1 month post-infusion, even in those patients who were previously refractory to blinatumomab and post-HSCT relapse. This evidence concerns the gene CD19 and acute lymphoblastic leukemia.