GCG and type 2 diabetes mellitus: The “ominous octet” term refers to the various parameters that impact the pathophysiology of T2D, including a decreased insulin secretion by pancreatic β-cells and an increased glucagon secretion by pancreatic α-cells, an increased hepatic glucose production, an increased lipolysis, an impaired brain appetite regulation, the decreased incretin effect at the intestinal level, increased renal glucose reabsorption and decrease in muscle glucose uptake, which represent the core to whom sharpen the T2D treatment (Table 1) [8].