As a matter of fact, anti-CD19 CAR T cells in an immunocompetent C57BL/6 mouse model showed successful efficacy in eradicating the CD19+ murine Eμ-ALL01 cell line with simultaneous onset of B cell aplasia as an on-target off-tumor effect, which resembles the results and safety profile obtained in clinical practice [52,53]. Here, CD19 is linked to neoplasm.