Although in the 2009 American Diabetes Association/European Association for the Study of Diabetes (ADA/EASD) consensus statement on management of hyperglycemia, only exenatide was included as second or third line option treatment for T2D [17], the subsequent 2012 ADA/EASD position statement has assigned to all incretin-based therapies a central role in T2D management [18]. Here, GCG is linked to type 2 diabetes mellitus.