Moreover, MuCCA1 and mIC-23 subcutaneous tumors from C57BL/6 mice displayed intense desmoplastic reaction and typical immunohistopathological features of cholangiocarcinoma, as evidenced by CK19 and a-SMA positivity and HNF4α negativity (Fig. S4G and S4J). Here, HNF4A is linked to cholangiocarcinoma.