GNAS and pancreatic intraductal papillary-mucinous neoplasm: Targeted genotyping (GNAS/KRAS) of cell-free DNA (cfDNA) from blood samples can also distinguish IPMN from control cases (sensitivity, 81%; specificity, 84.2%) and the amount of cfDNA detected is much higher in metastatic pancreatic ductal adenocarcinoma (PDAC) than in IPMN for differential diagnosis [51].