HNF4A and pancreatic intraductal papillary-mucinous neoplasm: The increased nuclear expression of HNF4α in non-invasive IPMN mirrors the expression pattern observed in PanIN in which isoform-specific expression patterns have not been studied, and in intestinal metaplasia in the stomach, which is characterized by synchronously increased P1 and P2 isoform expression14,15,21,22.