For instance, Chi et al. (2018) executed the meta-analysis and reported that mitogen-activated protein kinase 8 (MAPK8), cell division cycle 42 (CDC42), NADH:ubiquinone oxidoreductase core subunit S1 (NDUFS1), cytochrome C oxidase subunit 4I1 (COX4I1), and succinate dehydrogenase complex subunit C (SDHC) are the potential markers for PD diagnosis. Here, COX4I1 is linked to Parkinson disease.