FAS and inflammatory bowel disease: The signaling pathways involved in the IBD of MSCs therapy are mainly in the aspect of the immunology and inflammation (NF-κB pathway) [37, 85], the developmental biology signaling (wnt/β-catenin signaling interactive pathway and Notch signaling interactive pathway) [45, 69], PTEN/PI3K/Akt signaling resources [48], and apoptosis resources (FAS/FASL) [65].