However, further studies should be performed to identify the binding epitopes of the two VHHs, and to validate the functionality of VHH1-VHH2 CAR T-cells against tumor cells with some specific CD70 epitope loss that cannot be recognized by VHH1 CAR-T or VHH2 CAR-T or other published 70CAR- T. Besides, the CD70 gene was knocked-out in our nb70CAR-T, which produced a final product with a higher proportion of naïve phenotype CAR T-cells and lower expression of PD-1 and LAG3. The gene discussed is CD70; the disease is neoplasm.