GCG and diabetes mellitus: Previous study mentioned that GLP-1 could be used as a controller for diabetes and ultimately GLP-1 mimic and GLP-1R agonists such as liraglutide clinically could be used for patients with diabetes in the present time (Vilsboll and Holst, 2004; Amori et al., 2007; Campbell and White, 2008; Gallwitz, 2011; Duarte et al., 2013).