GLP-1 receptor agonists (incretin or GLP-1 mimetics) and dipeptidyl peptidase-4 (DPP-4) inhibitors (CD26 antigen inhibitors) are the currently available incretin-based therapies proven to be safe and effective in the management of type 2 diabetes (Amori et al. 2007). Here, GCG is linked to type 2 diabetes mellitus.