Direct comparison of the E18.5 Dsg1–/– mouse with AD revealed 26.5% of genes upregulated in the Dsg1–/– mouse are also upregulated in AD, whereas only 7.7% of genes downregulated in the Dsg1–/– mouse are also downregulated in AD (Figure 7, G and H and Supplemental Tables 5–8). This evidence concerns the gene DSG1 and Alzheimer disease.