According to the guideline, if a triple therapy (such as metformin, a Dipeptidyl peptidase-4-inhibitor and sulfonylurea) is not effective, not tolerated or contraindicated, then, it will be useful to consider combination therapy with metformin, a sulfonylurea and a Glucagon-like peptide-1 (GLP-1) mimetic for adults with type 2 diabetes. Here, GCG is linked to type 2 diabetes mellitus.