CD19 and acute lymphoblastic leukemia: In adult patients with B-NHL lymphomas and B-ALL, CD19-CAR T long-term persistence does not correlate with response to treatment and long-term cancer-free survival [163], whereas in pediatric ALL patients, persistence for over 6 months appears to be the determining factor for long-term leukemia clearance or leukemia recurrence in case of shorter CAR persistence [2].