Immunohistochemical expression of p16 was assessed in 195 tumors, including 102 primary ovarian tumors (51 mucinous, 47 endometrioid, and 4 mixed mucinous-endometrioid tumors), 82 metastatic adenocarcinomas of known primary sites (colorectum: 34, endocervix: 19, pancreaticobiliary tract: 17, appendix: 7, stomach: 5), 11 metastatic adenocarci-nomas of unknown origin, and 4 adenocarcinomas of uncertain origin. This evidence concerns the gene CDKN2A and adenocarcinoma.