In several mice, we also observed a spectrum of IPMN-like lesions or mixed MCN-IPMN histology with an intraductal proliferation of mucin-producing cells, the formation of papillae, and cystic dilatation of the pancreatic ducts (Fig. 4b). Here, MUC5AC is linked to pancreatic intraductal papillary-mucinous neoplasm.