This hypothesis is supported by recent findings that analogue compounds for the incretin hormone glucagon-like peptide-1 (GLP-1), which facilitate endogenous insulin release and are used to treat type 2 diabetes, reduce Aβ accumulation and rescue impairments in hippocampal synaptic plasticity and spatial learning and memory in transgenic mouse models of AD [12]–[14]. This evidence concerns the gene GCG and Alzheimer disease.