Shen et al., using a similar setup but with an in vitro model of Crohn’s disease, demonstrated that R. intestinalis stimulated thymic stromal lymphopoietin production in intestinal epithelial cells/CaCo-2 through TLR5, ultimately leading to dendritic cell activation and further to T-cell differentiation [65]. The gene discussed is TLR5; the disease is Crohn disease.