Oncogenes (RAS, ERBB2, BRAF, EGFR, PIK3CA, and CTNNB1) and tumor suppressor genes (p53, Smad4, and CDKN2A) are also involved in the development of intrahepatic cholangiocarcinoma (24–26). This evidence concerns the gene ERBB2 and intrahepatic cholangiocarcinoma.