CD276 and osteosarcoma: When the B7-H3 CAR-T cells were cultured for 10 days, we respectively co-cultured B7-H3 CAR-T cells with 4 osteosarcoma cell lines (HOS, U-2 OS, SW1353, Saos-2) at an effector-to-target(E:T) ratio of 2.5:1, while the NC-T cell group and tumor only group were used as the control group in the experiment.