As discussed above, GCGR antagonists (e.g., LY2409021, Volagidemab) have been considered as glucose-lowering therapy in T2DM patients, but these resulted in lipid disorders, whereas glucagon/GLP-1 receptors co-agonism improved dyslipidemia and reduced hepatic steatosis, which have brought up discussions regarding to the relationship between glucagon signaling and lipid metabolism [5,138,139]. Here, GCGR is linked to type 2 diabetes mellitus.