CDX2 and SATB2 are other useful markers for the differential diagnosis; generally, they are positive in case of gastro-intestinal/pancreato-biliary primitivity and negative in case of mammary primitivity, although, an important pitfall, an occasional weak reactivity for both markers has been reported also in primary breast carcinomas [33,34,35,36]. Here, CDX2 is linked to breast carcinoma.