GCG and type 2 diabetes mellitus: Exenatide (synthetic exendin-4 from Gila monster, Heloderma suspectum) is the first glucagon-like-peptide-1 (GLP-1) analogue (Furman, 2012) and has been used as an adjuvant in the treatment of type 2 diabetes mellitus (Nauck et al., 2007; Henry et al., 2014).