GCG and type 2 diabetes mellitus: GIP stimulates the α-cells to promote glucagon secretion, while GLP-1 reduces it.10,15 Elevation of glucagon is associated with T2D.16 Therefore, suppression of glucagon activity using a GLP-1 receptor (GLP-1R) agonist has been developed for treatment of T2D.17 The use of gastrointestinal hormones, particularly GLP-1 and GIP, includes incretin preparations such as a novel GLP-1R agonist or a GIP/GLP-1 dual agonist, which is anticipated to provide new means for controlling T2D and body weight.18–20