At the Abramson Center/UPenn and MSKCC, anti-CD19 CAR T cells produced complete remissions in 60–93% of B cell acute lymphocytic leukemia (B-ALL) and 50–93% overall responses in the treatment of B cell non-Hodgkin's lymphoma.103–108 In contrast to first-generation CARs, second-generation CAR T cells amplified in vivo and persisted for prolonged time in the peripheral blood upon application to lymphoma patients.109 While the first treatment responses were very similar, the respective CARs differ in their costimulatory domains with some differences in the response kinetics and pharmacology.110. Here, CD19 is linked to precursor B-cell acute lymphoblastic leukemia.