CD19 and acute lymphoblastic leukemia: CAR-transduced T lymphocytes, especially anti CD19-CAR T cells, have displayed impressive efficacy in patients with B cell malignancies, such as chronic lymphocytic leukemia (CLL), acute lymphoblastic leukemia (ALL), particularly relapsed/refractory B-ALL, non-Hodgkin lymphoma (NHL), and multiple myeloma (MM) [8–12].