The DEGs comparison between the AD datasets and its neurodegenerative comorbidities reveals the following overlapping genes: ACTB, CEACAM8, COX2, DEFA4, GFAP, MALAT1, RGS1, RPE65, SYT1, S100A8, S100A9, SERPINA3, TNFRSF11B and TUBB2A. This evidence concerns the gene DEFA4 and Alzheimer disease.