PDCD1 and pancreatic intraductal papillary-mucinous neoplasm: Here, the expression levels of PD-1 on peripheral T lymphocytes were detected using flow cytometry in128 patients including 68 newly diagnosed PDAC patients(31 female and 37 male patients with a median age of 60 years; age range, 38–78 years), 40 patients with IPMN(17 female and 23 male patients with a median age of 63 years; age range, 41–82 years) and 20 healthy donors (10 female and 10 male patients with a median age of 62 years; age range, 40–79 years).