QRFPR and pancreatic insulinoma: Although initially not found in mouse and rat pancreas (91, 92), expression of QRFP26/QRFP43 and QRFPR mRNA and protein was later found in human endocrine pancreas and isolated pancreatic islets (107, 111), rat INS-1E β-cells (111), and mouse insulinoma MIN6 cells (107).