In the Sleeping Beauty-engineered donor-derived CAR T-cell therapy for B-ALL patients relapsed after allo-HSCT, 2 of the 6 MRD-negative CR patients received consolidative allo-HSCT and remained leukemia-free, the other 4 did not receive second allo-HSCT and 2 relapsed with CD19-positive disease [59]. The gene discussed is CD19; the disease is acute lymphoblastic leukemia.