For PIT of CCA, there have been two preclinical reports: one used anti-EGFR and HER2 antibodies [88], while another used an antibody against trophoblast cell surface antigen 2/tumor-associated calcium signal transducer 2 (TROP2), which is overexpressed in trophoblast cancer and many epithelial cancers, including pancreatic cancer and CCA [101]. The gene discussed is TACSTD2; the disease is cholangiocarcinoma.