Blood samples were obtained from patients with pancreatic cancer or IPMN between January 2012 and February 2016 at the Osaka Medical Center for Cancer and Cardiovascular Diseases. Plasma preparation and DNA extraction were performed as described previously . Tissue samples were obtained using endoscopic ultrasound-guided fine-needle aspiration. Written informed consent was obtained from all the patients. This study was approved by the ethics committee of the O Osaka Medical Center for Cancer and Cardiovascular Diseases.