The tumor cells were negative for: pan-cytokeratin (CK MNF 116); cytokeratins 5, 7, 19, and 20; epithelial membrane antigen (EMA); GATA binding protein 3 (GATA3); hepatocyte-specific antigen; P63; prostate-specific antigen (PSA); thyroid transcription factor 1 (TTF1); paired box 8 (PAX8); caudal type homeobox 2 (CDX2); carcinoembryonic antigen (CEA); CgA; secretagogin; steroidogenic factor 1 (SF1); inhibin alpha; glucagon-like peptide 1 (GLP1); and pancreatic and duodenal homeobox 1 (PDX1) (data not shown). The gene discussed is PDX1; the disease is neoplasm.