GNAS and pancreatic intraductal papillary-mucinous neoplasm: On the other hand, pancreatobiliary subtype IPMNs are known to have aggressive biological behaviors with inconspicuous mucin secretion and highly prevalent KRAS mutation21,24,25, explaining why two IPMN cases with HGD/INV (case #90 and #111) harboring the KRAS mutant in cfDNA showed wild-type GNAS genotype in the primary lesions.