New discovery that GLP-1 and Exendin-4 (Ex-4), a naturally occurring stable analogue of GLP-1 that binds at the GLP-1 receptor (GLP-1R), possess neurotrophic properties and can protect neurons against glutamate-induced apoptosis and reduce level of Aβ in brain, prompt a new consideration: GLP-1 and its mimics are promising agents in therapy of AD. Here, GCG is linked to Alzheimer disease.