NPPA and pancreatic insulinoma: As already mentioned, it was also shown that ANP can stimulate the proliferation of cultured rat pancreatic islets β-cells and insulinoma cells (INS-1E) via GC-A/cGMP-dependent activation of phosphatidylinositol 3′-kinase and Akt/Foxo1a/cyclin-D2 signaling [16].