GCG and Alzheimer disease: We directly compared β-arrestin-2 conformational activation kinetics in response to hGIP (1 μM) and GIP108 (1 μM) by the human and mouse SNAP-tagged GIPRs expressed in AD-293 cells, and GLP-1 (10 nM) and liraglutide (10 nM) at the corresponding GLP-1Rs (Figure 3A–D).