GLP1 receptor (GLP1R) a seven-transmembrane family B G protein-coupled receptor (GPCR) locus : 6p21.2 [§§; ^], with a N-terminal extracellular domain is a potent insulinotropic incretin hormone important in maintaining blood glucose homeostasis, through their receptors, GLP1R and glucose-dependent insulinotropic polypeptide GIPR. The glucagon-like peptide-1 (GLP-1) C-terminal regions bind to the N terminus (NTD) this region of interaction is mediated by the nGLP1R (receptor variants) released from the gut as an incretin and oxyntomodulin (OXM) and DPP-IV inhibitors are structurally related gastrointestinal hormone secreted from enteroendocrine L cells into the blood stream governed by the tethered (beta)arr2. GLP-1R and the GIP receptor (GIP-R) affect the (ligand-dependent signal bias of extracellular loop-ECL2 mutations) pharmacological properties (exendin-4 (from the venom of the lizard Heloderma suspectum) is used in humans, as a therapeutic tool: liraglutide) of these proteins, is neuroprotective. GLP1 and GLP1R are expressed in the brain and associated mechanisms in the central nervous system, regulation of neuroendocrine and behavioural responses in certain cells in the brain. TCF7L2 and GLP1R/GIPR expression effects on beta-cell function was decreased in human T2DM islets is a characteristic feature of NIDDM. GLP-1 stimulate secretion of pituitary hormones. GLP1 is a hormone derived from the preproglucagon molecule (GCG). GLP1 a Glucagon Receptor Antagonist dose not bind peptides of related structure glucagon, (GCG) does not modify (Unrelated, non-diabetic Pima Indians) the growth or apoptosis of a seven transmembrane (TM) domain protein (GLP1) in normal human pancreas ectopic expression of the pancreatic master regulator PDX-1* (pancreatic and duodenal homeobox gene 1) neuroendocrine transdifferentiation* of pancreatic ductal cells within the endocrine pancreas. The activity of this receptor is mediated by G proteins which activate adenylyl cyclase, ADCY8 (brain) plays a central role including signalling via the GLP1R.