GCG and diabetes mellitus: From a mechanistic standpoint, vildagliptin corrected the impaired phosphorylation of cAMP response element binding protein (CREB), protein kinase B/Akt (PKB/Akt), S6-ribosomal protein (S6RP), and insulin receptor substrate (IRS) 2 in DRG of diabetic models, suggesting that vildagliptin restores the diabetes-induced impairment of GLP-1 and insulin signaling that play important roles in neurite growth and cell survival, thereby exerting protective effects against diabetic neuropathy [88].