In a second study analyzing the expression of claudins in intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs), both considered definitive premalignant pancreatic lesions, Lee and co-workers reported that both IPMNs and MCNs were positive for claudins-2, -4, and -18 in similar percentages, albeit there was slightly increased intensities of the expression of all above claudins in IPMN than in MCN [51]. This evidence concerns the gene CLDN2 and pancreatic intraductal papillary-mucinous neoplasm.