TGFA and cholangiocarcinoma: found that the epidermal growth factor receptor (EGFR) pathway also contributes to the invasion, metastasis, and development of CCA.27 EGFRs on cell membrane can bind with their ligands such as transforming growth factor α (TGF‐α) to activate protein kinases to promote CCA growth and the overexpression of EGFRs can be effective prognostic factors for intrahepatic CCA.28 In addition, activated EGFRs can regulate a few intracellular signalling pathways to influence cholangiocarcinogenesis.