Recently, there has been interest in the repurposing of clinically used drugs on off-labeled conditions and among them is the use of glucagon-like peptide-1 receptor agonists (GLP-1RAs), a medication for lowering blood sugar in T2DM, for PD (Aviles-Olmos et al., 2013b). Here, GLP1R is linked to type 2 diabetes mellitus.