GCG and type 2 diabetes mellitus: Upon activation by endogenous ligand, oleoylethanolamide (OEA), the resultant accumulation of intracellular cAMP via adenylate cyclase activation enhances the effect of glucose-stimulated insulin secretion (GSIS) and GLP-1 release, thus GPR119 represents a promising target for the treatment of type 2 diabetes [7], [9], [10] and a potential product development attraction to many drug makers.