CD19 and acute lymphoblastic leukemia: At the NCI 4/9 pediatric and young adult B-ALL patients (some relapsing with CD19-negative disease after CART19) treated with CART22 reached MRD-negative CR [41], [42], [43] At the University of Pennsylvania/Children's Hospital of Philadelphia two CART22 trials (NCT02588456; NCT02650414) recently opened for adults and pediatric patients with r/r B-ALL.