Autologous T cells are genetically engineered to express a CD19-specific chimeric antigen receptor containing CD3ζ and a costimulatory domain. Upon binding CD19 on malignant and normal B cells, the CAR triggers T-cell activation, proliferation, and cytotoxic effector functions (perforin/granzyme release and cytokine-mediated killing), leading to apoptosis of CD19+ B-lymphoblasts and on-target B-cell aplasia.