TP53 and pancreatic intraductal papillary-mucinous neoplasm: Since GNAS mutations have been shown to occur early on in the neoplastic progression of IPMN, while P53 mutations tend to be associated with more high-grade or invasive lesions [21], it is possible that GNAS and KRAS statuses may be more appropriate for use as factors, from a chronological progression viewpoint.