GCG and type 2 diabetes mellitus: The incretin glucagon-like peptide-1 (GLP-1), released from the gut during food intake, amplifies glucose-stimulated insulin release by binding to and activating its cognate G protein-coupled receptor (GPCR), the GLP-1 receptor (GLP-1R), triggering cAMP generation and downstream Protein Kinase A (PKA) and Exchange Protein Activated by cyclic AMP 2 (Epac2) signalling4, a process that has been exploited to develop pharmacological GLP-1R agonists (GLP-1RAs) as T2D therapies.