Tofactinib is a JAK inhibitor that targets mainly JAK 1 and JAK3 approved to treat Ulcerative Colitis (UC) in 2018. The JAK inhibitor Upadacitinib (upa) was recently approved to treat UC in March 2022 and has increased selectivity for JAK1. The relative efficacy and safety of these two JAK inhibitors is not presently clear. An important clinical question is whether patients who have not responded or lost response to tofacitinib will have a reasonable likelihood of response with upadacitinib.