IL9 and irritable bowel syndrome: Targeting the Janus Kinase Signal Transducer and Activator of Transcription (JAK-STAT) pathway is a potentially effective therapeutic strategy for IBD because cytokine mediators of inflammation, including interferon-gamma (IFN-γ) and interleukin (IL-9, IL-12, and IL-23), rely on the signaling of this pathway and Sphingosine-1-phosphate is a sphingolipid ligand that binds to G protein-coupled receptors (S1P1–S1P5), controlling lymphocyte migration from lymphoid tissue into circulation.