Table 4 summarizes the frequencies of genetic abnormalities in mucinous ovarian and colorectal carcinomas [50,51,52,53,54,55,56,57,58,59,60]. Since ovarian mucinous carcinomas frequently express proteins such as cytokeratin (CK) 7, CK 20, caudal-related homeobox transcription factor (CDX) 2, mucin (MUC) 2, and MUC5AC, they are suggested to have biological characteristics similar to those of gastrointestinal carcinomas [61,62]. Table 5 summarizes the frequencies of protein expression in mucinous ovarian and colorectal carcinomas [63,64,65,66,67,68,69,70,71,72,73]. This evidence concerns the gene MUC5AC and digestive system carcinoma.