Mutations in APC or CTNNB1, both of which belong to the Wnt/β-catenin pathway, were observed in non-intestinal IPNBs, particularly pancreatobiliary subtype, but these mutations are not or are only rarely observed in IPMN [130,136,137], thus these IPNB with activation of the Wnt/β-catenin signaling pathway may not be a biliary counterpart of IPMN [130,136]. Here, CTNNB1 is linked to pancreatic intraductal papillary-mucinous neoplasm.