GCG and pancreatic neuroendocrine tumor: In order to approach the cell cultures characterization, we studied, by confocal immunoflourescence (IF) microscopy, several pancreatic islet markers, such as insulin, glucagon, C-peptide, Glut-2 and PDX-1, as well as ductal (cytokeratin 19), mesenchymal (alpha-actin, desmin and vimentin) and one of the endocrine pancreatic tumor (chromogranin) cell markers.