Intestinal IPNBs subclassified into type 1 were associated with KRAS, GNAS and RNF43 mutations which are reportedly common in IPMNs [132,136], indicating that type 1 IPNB was a biliary counterpart of IPMN [111,130,132,133,135]. The gene discussed is GNAS; the disease is pancreatic intraductal papillary-mucinous neoplasm.