However, the more amount of CD3-positive cells in the tumor stroma of CAR-T group and CAR-T plus anti-PD1 group compared with blank T group were likely due to the presence of more CAR-T cells, based on our result in vitro that anti-HER2 CAR-T cells could expand better after co-cultured with HER2+ target cells, and the addition of anti-PD1 could further enhance their expansion. The gene discussed is ERBB2; the disease is neoplasm.