EGFR and intrahepatic cholangiocarcinoma: To test the practicability of applying our incorporated RNA ISH and ICC staining on viral targets, a staining pattern of DAPI, CK-AF488 (ICC), HPV16 E6/E7-type 1 (RNA ISH), and EGFR-AF647 (ICC) was used on HPV-positive and -negative cell lines.