Understanding Ozanimod's MOA Via Mass Cytometry in Ulcerative Colitis

This study uses mass cytometry — a high-tech method that can measure dozens of immune cell types at once — to understand exactly how ozanimod (a medication approved for ulcerative colitis) works in the body. The goal is to learn more about the drug's mechanism and identify which patients are most likely to respond to it. **You may be eligible if...** - You are 18 years or older - You have been diagnosed with ulcerative colitis (UC) for at least 3 months, confirmed by both camera examination (endoscopy) and tissue analysis - Your UC is currently active - Your doctor is already considering starting you on ozanimod and is not combining it with biologic medications **You may NOT be eligible if...** - Your doctor believes you may need surgery (colectomy or ileostomy) within 3 months - You have fulminant (extremely severe) colitis, toxic megacolon, or bowel perforation - You have had your colon surgically removed - You have a low platelet count or an active gut infection Talk to your doctor to see if this trial is right for you.