KRT7 and mucinous adenocarcinoma: Furthermore, combined use of CDX2 with CK7 can help in this differential diagnosis, as 60% of the primary ovarian mucinous tumors are (CK7+, CDX2−, in contrast to mucinous adenocarcinomas of the lower gastrointestinal tract, where 83% of cases are (CK7−, CDX2+) [4, 7, 22].