CD19 and acute lymphoblastic leukemia: Given the superior results in younger patients, age and bone marrow health may play a significant role in their response to transplant post CAR T. In a phase I/II trial, 18/45 patients who were in an MRD-negative CR after receiving CD19 CAR T for B-ALL received an allo-HCT and experienced a higher probability of EFS and OS compared to the other patients with high risk of relapse who did not receive an allo-HCT [32].