The liver core biopsy was sent to our institution for consultation as “adenocarcinoma ER/TTF-1/GATA3/CDX2 negative, possible CUP.” Based on the morphology of well-differentiated glands in sclerotic stroma, a diagnosis of “intrahepatic cholangiocarcinoma” (Fig. 1D) with lung metastases was given, and the patient was treated accordingly. Here, TTF1 is linked to adenocarcinoma.