First, besides T2DM-associated animals, GLP-1 mimetics were shown to ameliorate markers of peripheral insulin resistance, including abnormally raised plasma insulin (Li et al., 2010b), circulatory glucose (Li et al., 2010b; Holubova et al., 2019) and glycated hemoglobin A1c levels (Li et al., 2010b), which is a clinical marker for T2DM that reflects the plasma glucose levels over the last 3 months (Sequeira and Poppitt, 2017), in AD animal models. Here, GCG is linked to type 2 diabetes mellitus.