GCG and type 2 diabetes mellitus: The biological functions of GLP-1 include stimulating insulin secretion in a glucose-concentration-dependent fashion, suppressing glucagon release, promoting satiety, and increasing peripheral glucose disposal, all of which render this incretin to be an attractive therapeutic target for T2DM (Baggio and Drucker, 2007; Brubaker, 2010; Donnelly, 2012).