Mutated K-RAS gene was detectablein activated chromatin in pancreatic juice secreted after surgical resection ofpancreatic, ampullary and bile duct carcinomas and directly correlated with thenumber of CTC found in the portal venous blood (P = .0453).ChIP and ChIP-Seq detected acetylated chromatin in peri-ampullary cancer patientjuice containing candidate chromatin loci, including RETproto-oncogene, not found in similar analysis of pancreatic juice fromnon-malignant ampullary adenoma. Here, KRAS is linked to carcinoma of the ampulla of vater.