For example, FAP and gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) are sometimes collectively referred to as APC-associated polyposis [9, 21], while diseases that result in adenomatous polyposis, including FAP, are occasionally grouped under the term “adenomatous polyposis syndrome” [9]. Here, APC is linked to gastric adenocarcinoma and proximal polyposis of the stomach.