PGR and adenocarcinoma: We aimed to explore the utility of immunohistochemistry profiles, i.e. the expression of p16, carcinoembryonic antigen (CEA), vimentin, estrogen receptor alpha (ER) and progesterone receptor (PR), in tissue microarrays in archived samples of ADC that had been tested for HPV DNA, and in particular to assess if it would be possible to define the tissue of origin of HPV negative adenocarcinoma samples.