<qa>  What is the goal of this clinical trial?The goal of this clinical trial is to study how approaches for manufacturing chimeric antigen receptor CAR-modified T CAR-T cells affect their in vivo persistence and therapeutic efficacy against B lymphoma. Recently, cancer immunotherapy, treatments aiming to arm patients with immunity specifically against cancer cells, has emerged as a promising therapeutic strategy. Among the many emerging immunotherapeutic approaches, clinical trials utilizing CARs against B cell malignancies have demonstrated remarkable potential. CARs combine the variable region of an antibody with T-cell signaling moieties to confer T-cell activation with the targeting specificity of an antibody. Thus, CARs are not MHC-restricted so they are not vulnerable to MHC down regulation by tumors. However, defined by the activation and contraction program of their mother cells, the persistency and function of CAR-T cells are also restricted by the protocol of manufacturing. Previous clinical studies largely utilized interleukin-2 IL-2 for the ex vivo expansion of CAR-T cells, which preferentially generate CAR-T cells with characteristics of terminally differentiated effector cells. Our preliminary data indicated that two common gamma chain cytokines, IL-7 and IL-15, can help to selectively expand CAR-T cells with various memory phenotypes. CAR-T Cells prepared under this condition resulted in improved therapeutic efficacy in preclinical animal models. This clinical investigation is to test a hypothesis whether IL-7IL-15-programmed anti-CD19 CAR-T cells persist longer in lymphoma patients after infusion and whether the persistency of CAR-T cells can lead to improved anti-lymphoma efficacy. 