ERBB2 and intrahepatic cholangiocarcinoma: HER2 aberrations were found in 5.8% (3/52) of intrahepatic cholangiocarcinoma patients, 13.9% (5/36) of extrahepatic cholangiocarcinoma patients, 36.4% (8/22) of gallbladder cancer patients, and 18.2% (2/11) of ampulla of Vater cancer patients.