CEACAM5 and squamous cell carcinoma: EMA: Epithelial membrane antigen, CEA: Carcinoembryonic antigen, GCDFP: Gross cystic disease fluid protein, PCK: Pan-cytokeratin, NAD: Nothing abnormal detected, SCC: Squamous cell carcinoma, PDSCC: Poorly differentiated squamous cell carcinoma, MDSCC: Moderately differentiated Squamous cell carcinoma, IHC: Immunohistochemistry