G protein-coupled receptor 119 (GPR119) is a member of the class A (rhodopsin-type) GPCR family, which is highly expressed on only a limited number of tissues, such as pancreatic β-cells and enteroendocrine cells of the gastrointestinal tract in humans. The activation of GPR119 has the stimulatory effects of glucose-dependent insulin secretion in pancreatic β-cells as well as intestinal secretion of incretin hormones including glucose-dependent insulinotropic peptide (GIP) and glucagon-likepeptide1 (GLP-1). Taken together, these effects represented a potential mechanism for modulation of glucose homeostasis and an attractive approach to the treatment of type 2 diabetes mellitus (T2DM). GPR119 can be activated by oleoylethanolamide and several other endogenous lipids containing oleic acid: these include N-oleoyl-dopamine, 1-oleoyl-lysophosphatidylcholine, generated in the tissue, and 2-oleoyl glycerol generated in the gut lumen.