These overall results also confirm a delay in DN progression promoted by sitagliptin, possibly via the inhibition of ERK1/2 signalling which seems to be activated by AGEs and is implicated in epithelial-myofibroblast transition [185]; by decreased TGF-β1 expression, a cytokine associated with inflammatory responses in T2DM, which has been recognized to be involved in the development of glomerulosclerosis and interstitial fibrosis; and by increasing the interaction between GLP-1 and the GLP-1R [186]. Here, GCG is linked to type 2 diabetes mellitus.