Recent report showed that when divided into intrahepatic and extrahepatic locations, intestinal IPNBs arising in the intrahepatic bile ducts and belonging to type 1 frequently present with GNAS, KRAS and RNF43 mutations [132,135], suggesting that intestinal IPNBs, particularly those arising in the intrahepatic bile duct, show similar mutations as in IPMN [111,132,133,135]. Here, RNF43 is linked to pancreatic intraductal papillary-mucinous neoplasm.