Exploring the expression of genes with known roles in tumor immunology reveals two important observations: 1) markers of immune cell infiltration, including CD8, CD3, CD19 and CD2, show similar expression in IBD-FID and IBE-FID subgroups (Figure 4A); while (2) markers of immune functional orientation, including CXCL10 (tissue rejection chemokine), GZMB (cytotoxic effector molecule), INFG and STAT1 (Th1 polarization), show differential expression across IBD-FID and IBE-FID groups (Figure 4B). Here, CD8A is linked to irritable bowel syndrome.