CLDN18 and pancreatic intraductal papillary-mucinous neoplasm: Highest expression of claudin-2 seen in adenomas in both IPMN and MCNClaudin-2 expression decreased with increased gradeClaudin-4 expression increased with increased gradeCancer arising in IPMN and MCN showed strong claudin-18 expression in poorly differentiated regionsIPMN and MCN lesions with mild dysplasia exhibited weaker claudin-18 expressionClaudin-2 expression decreased with increased histological grade in IPMN and MCN lesionsClaudin-4 expression increased with increased histological grade in IPMN and MCN lesions