In addition, although inactivating mutations in Ring finger protein 43 (RNF43), which encodes a ubiquitin ligase involved in WNT signaling (often with loss of heterozygosity) are also common in IPMNs (36), the precise timing of the occurrence of RNF43 mutations in IPMN tumorigenesis has not yet been clarified to date. Here, RNF43 is linked to pancreatic intraductal papillary-mucinous neoplasm.