GCG and type 2 diabetes mellitus: The critical role of GLP-1 in glucose homeostasis, food intake, and energy metabolism has led to the development of multiple FDA-approved GLP-1 analogs, such as exenatide, liraglutide, and semaglutide, for type 2 diabetes treatment (Agersø et al., 2002; Estall and Drucker, 2006; Eng et al., 2014; Lau et al., 2015).