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]. This evidence concerns the gene PSEN1 and Parkinson disease.