(iii) O-linked glycosylation of mucins, notably apomucins MUC5AC and MUC1, but not MUC2 or MUC6, that define the IPMN pancreatobiliary subtype with PDAC-associated IPMN clustering. This evidence concerns the gene MUC6 and pancreatic intraductal papillary-mucinous neoplasm.