GBP1 and intrahepatic cholangiocarcinoma: GBP1 protein expression in the cell lines was further evaluated with ICC as shown in Figure 1E, where variable GBP1 expression is shown in the parental DU145 (1Ea) and PC3 (1Ec) cells, but the GBP1 protein expression in the DU145 GBP1 KO (1Eb) and PC3 GBP1 KO (1Ed) cell lines disappeared.