Although the interaction between S1PR2/Cathepsin B and M2-mAchR/TLR2 pathways is not clearly understood, considering the close relationship between pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) and the occurrence of colitis, these pathways may both contribute to the high level DCA induced inflammatory injury in colon. The gene discussed is TNF; the disease is colitis.