Twelve days after CAR T cell infusion, complete tumor rejection was observed in mice treated with RP-B7-H3 CAR T from patients with metastatic breast cancer; 12 days after CAR T cell infusion, complete tumor rejection was found in 40% (8/20) of mice treated with RP-B7-H3 CAR T, while 5% (1/20) of the mice treated with NRP-B7-H3 CAR T cells derived from the same set of patients (Fig. 6c) exhibited complete tumor rejection. Here, CD80 is linked to neoplasm.