DPP4 and obesity due to melanocortin 4 receptor deficiency: Experimental studies provide first evidence for a modulating effect of GLP-1 on inflammatory cells, and it has been recently published that the GLP-1 degrading enzyme dipeptidylpeptidase-4 (DPP-4) promotes vascular adipose tissue inflammation and insulin resistance in obesity [239], also suggesting a potential role of broader “metabolic alterations” in redox-mediated inflammation.