GLP-1 mimetics, e.g., liraglutide, exenatide, or lixisenatide, showed neuroprotective properties in the 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model (Li et al., 2009; Liu et al., 2015; Yuan et al., 2017; Chen et al., 2018; Lin et al., 2021), and liraglutide is currently being tested in a phase II trial in PD patients (clinical trial identifier NCT02953665). This evidence concerns the gene GCG and Parkinson disease.