CD55 and pancreatic intraductal papillary-mucinous neoplasm: CD55 concentrations in invasive IPMN (mean: 1.354 ng/mL, STDEV: 1.532 ng/mL) were significantly higher than in LGD (mean: 0.598 ng/mL, STDEV: 1.045) (p < 0.05).