To determine the therapeutic index of the CAR-T cells with different scFvs and identify a CAR which can mitigate OTOT, we tested the cytotoxicity of CAR-T cells on CAIX high skrc-59 ccRCC cells and CAIX low MMNK-1 cholangiocytes using an image-based assay developed in our lab [17]. This evidence concerns the gene CA9 and nonpapillary renal cell carcinoma.