The first GLP-1 analog to be approved by FDA in 2005 for the management of Type 2 diabetes was the chemically synthesized Exenatide under the name of Byetta (186), a formulation of the DPP-IV resistant peptide discovered in the gila monster Heloderma suspectum saliva in 1992 (187). This evidence concerns the gene GCG and type 2 diabetes mellitus.