TTF1 and neoplasm: Immunohistochemically, the tumor cells were positive for cytokeratin AE1/AE3, Vimentin, and thyroid transcription factor-1 (TTF-1), while they were negative for caudal-related homeobox 2 (CDX2), cytokeratins 20 (CK20), hepatocyte paraffin-1 (HepPar-1), glypican-3 (GPC3), and S100 calcium-binding protein P (S100P).