Antitumor ability of γδT, CAR-γδT, and 7 × 19 CAR-γδ T cells both in vitro and in MCF-7 CDX model. (a) FACS analysis of the expression level of FRa in human TNBC cell line MDA-231, MDA-436, MDA-468, human breast cancer cell line MCF-7, and human ovarian cancer cell line C30. (b) FRa-specific cytotoxicity curves of γδT, CAR-γδT, and 7 × 19 CAR-γδ T cells against FRa negative expression C30 (left), FRa moderate expression MDA-MB-231 (middle), and FRa overexpression MCF-7 (right) tumor cell lines at the ratio of 1 : 1, 5 : 1, 10 : 1, respectively. (c) Histograms showed IFN-γ secretion of γδT, CAR-γδT, and 7 × 19 CAR-γδT against C30, MDA-MB-231, and MCF-7 at the ratio of 10 : 1. The IFN-γ production was detected using ELISA. (d) Tumor volume curves of FRa overexpression in MCF-7 CDX models. Quantification of tumor volumes (mm3) in the PBMC, γδT, CAR-γδT, and 7 × 19 CAR-γδ T treatment groups.