Exendin-4 (Ex-4), a GLP-1 receptor agonist that has been used as a drug injected subcutaneously for treatment of T2DM, was shown to promote adiponectin secretion via the protein kinase A (PKA) pathway in 3T3-L1 adipocytes and ameliorate insulin resistance [12]. Here, GLP1R is linked to type 2 diabetes mellitus.