The IHC profile of different histological types of carcinomas allows them to be distinguished; for example, the pancreaticobiliary type expresses CK7 and mucin 5a (MUC5a), and the intestinal type expresses CK20, caudal-type homeobox 2 (CDX2) and mucin 2 (MUC2) (Table 1) [30]. This evidence concerns the gene MUC2 and carcinoma.