Using PDX models which recapitulate the complex biology and heterogeneity inherent to patient tumors, we demonstrated that our B7H3.CAR EBVSTs displayed good antitumor activity and significantly improved survival not only in a highly B7-H3–positive breast cancer PDX model, but also in a NSCLC PDX where B7-H3 expression was considerably weaker. The gene discussed is CD276; the disease is breast cancer.