Next, to evaluate whether the increased anti-tumor activity depend on the expression level of PD-L1 on target cell, we investigated the antitumor efficacy of HER2.28ζ/PD-L1.BB CAR-T cells in an abdominal metastasis model of parental SKOV3 cells with moderate PD-L1 expression as shown above. Here, ERBB2 is linked to neoplasm.