ERBB2 and intrahepatic cholangiocarcinoma: We classified HER2 protein status into four groups based on the results of IHC: IHC 0, 1 + , 2 + , and 3 + but found HER2 protein status are not significantly related to clinicopathological features of ICC (Fig. 3b, Supplemental Fig. 1b–d and Supplemental Table 2).