CXCR5 and biliary tract cancer: Yet, clinical studies are underway to investigate the therapeutic efficacy of C-X-C chemokine receptor type 5 (CXCR5)-expressing EGFR-CAR T-cells, transforming growth factor-beta (TGF-β) knockout EGFR-CAR T-cells, and IL-12-secreting EGFR-CAR T-cells in NSCLC, advanced biliary tract cancer, and colorectal cancer (CRC), respectively (NCT04153799, NCT04976218, and NCT03542799).