In thepancreas of untreated but diabetic animals expression of HNF4alpha, insulin1,insulin2 and of phosphoenolpyruvate carboxykinase was significantly repressed.Furthermore, cyclosporine treatment of the insulinoma-1E cell line resulted inremarkable reduction in HNF4alpha protein and INS1 as well as INS2 geneexpression, while transcript expression of HNF4alpha, apolipoprotein C2,glycerolkinase, pyruvatekinase and aldolase B was repressed in treated Caco-2cells. The gene discussed is APOC2; the disease is pancreatic insulinoma.