Among these DEGs, 652 genes were upregulated, while 1025 genes were downregulated, as depicted in Figure 2A. The expression profiles of the top 23 upregulated and downregulated DEGs are presented in Figure 2B. By intersecting the CRC-related protective causal genes obtained from SMR analysis with the downregulated DEGs of AD, we identified three shared genes: ITCH, TNNC1, and TET2, as shown in Figure 2C. The validation of the shared genes was conducted using a cohort of CRC samples from TCGA (Figure 2D-2E) and AD datasets GSE121212 (Figure 2F). Here, ITCH is linked to Alzheimer disease.