To evaluate the effect of anti-PD-1/PD-L1 blockade on CAR-T cells and determine whether it could restore their tumor-killing ability in this model, we first confirmed the expression of PD-L1 and PD-1 in tumor cells and hypofunctional CAR-T cells, respectively (Figures S1D and S1E). Here, PDCD1 is linked to neoplasm.