CD19 and acute lymphoblastic leukemia: Furthermore, when evaluating the levels of IFN-γ or TNF-α released by CD19 CAR T cells or control CAR T cells, we did not observe a significant reduction in IFN-γ (Fig. 3C) or TNF-α production (Fig. 3E) from CD19 CAR T cells when they were cocultured with hCD19+ B-ALL cells.