KRAS and pancreatic intraductal papillary-mucinous neoplasm: Mutation in GNAS involving codon 201 is observed frequently in IPMN lesions, either by itself or in combination with mutant KRAS (Amato et al., 2014; Fukayama et al., 1986; Wu et al., 2011), and adjacent invasive PDAC, identifying GNAS as a driver in IPMN-derived PDAC.