S1PR1 and ulcerative colitis: Several new biologics—mirizikizumab (IL-23 blocker), tofacitinib and upadacitinib (JAK inhibitors, ozanimod and etrasimod (sphingosine-1-phosphate receptor modulators))—have been approved for the treatment of moderate to severe ulcerative colitis, and these new agents add novel mechanisms of action to the expanding therapeutic tools of advanced therapies in the treatment of ulcerative colitis [6,7].