We were specifically drawn to a group of genes that were significantly dysregulated in blood and brain, including Necab3, Apbb2, App, Psen1, Saa1, Prkcg, Park2, Snca and Prnp, because of their involvement in neurodegenerative diseases, such as Alzheimer’s and Parkinson’s disease [14]–[16], [18], [20]–[23]. The gene discussed is PRNP; the disease is Parkinson disease.