GZMB and renal cell carcinoma: Granzyme B staining showed the highest percentage of 2+/3+ positive cells in the RCC tumors treated with the anti-CAIX CAR T cells secreting anti-PD-L1 IgG4 followed by anti-PD-L1 IgG1-secreting cells, both of which were higher than parental anti-CAIX CAR T cells and other control groups (Figure 5B and 5C).