TLR9 and irritable bowel syndrome: Genes related to immune response such as CD1D, IRF7, TNFSF13, IRF5, TLR9, LYZ, ICAM1 and CX3CL1 showed higher expression in colonoid monolayers stimulated with fecal supernatants from IBS patients, while TLR5 expression was higher in colonoid monolayers stimulated with fecal supernatants from healthy subjects (Figure 4C).