For further verification, we checked the number and p-value of the identified DEGs of the PD-related KEGG pathway, including the “toll-like receiver signaling pathway,” “TGF beta signaling pathway,” “PI3K Akt-signaling pathway,” “MAPK signaling pathway,” “calcium signaling pathway,” and “Apelin-signaling pathway” (Fig. 3F, G). Here, APLN is linked to Parkinson disease.