GLP1R and Alzheimer disease: First clinical trials have shown that GLP-1 receptor agonists can improve clinical pathologies of PD and AD, including prolonged benefits on cognition and motor symptoms, and are a proof of concept (Aviles-Olmos et al., 2013, 2014; Athauda et al., 2017, 2019a; Athauda and Foltynie, 2018; Edison et al., 2021).