In cytotoxicity assays against chordoma cells performed at different time points, B7–H3 CAR-T/IL-7 cells remained lethal to chordoma cells on day 17, and the addition of IL-7 mAb to the B7–H3 CAR-T/IL-7 and chordoma cell co-culture system attenuated the sustained killing of tumor cells. The gene discussed is IL7; the disease is chordoma.