GCG and type 2 diabetes mellitus: However, the rapid degradation of native human GLP-1 by dipeptidyl peptidase 4 (DPP-4) has limited its clinical application and prompted the development of GLP-1 analogues (e.g., liraglutide, exenatide, semaglutide, lixisenatide) that are resistant to DPP-4 cleavage, which are now used for treating T2DM [12].