CA9 and renal cell carcinoma: A self-inactivating bi-cistronic CAR-T targeting CAIX, fused with a CD28ζ endodomain and designed to locally release anti-PD-L1 antibodies at RCC sites, demonstrated heightened antitumor efficacy and reduced T-cell exhaustion markers in a humanized mouse model of CAIX+PD-L1+RCC (104).