DPP4 and obesity due to melanocortin 4 receptor deficiency: Promising results from the latest research on obesity and IR indicate the therapeutic potential of GPR120 activation, especially in combination with incretin (GLP-1), in enhancing the activity of dipeptidyl peptidase-IV (DPP-IV) inhibitors, which effectively stimulate the proliferation of β-cells [222,223,224,225].