Define Predictors of Response to Ozanimod in UC Discovering Biomarkers in the Management of Ulcerative Colitis

Inclusion Criteria: 1. Patients ≥18 years of age with established diagnosis of UC starting ozanimod therapy as part of their clinical care 2. Patients with moderate to severe UC, determined by a 3-component Mayo score of 5-9 with an endoscopic subscore ≥ 2.Endoscopy must be performed within 90 days of ozanimod initiation 3. Elevated CRP (greater than upper limit of normal on assay) and/or fecal calprotectin (\>250 mcg/g) within 90 days of drug initiation Exclusion Criteria: 1. Diagnosis of Crohn's disease or indeterminate colitis 2. Total (procto)colectomy 3. Ileoanal pouch anastomosis 4. Current ileostomy or colostomy 5. Untreated Clostridium difficile infection 6. Known pregnancy