EBI2 is a risk gene for inflammatory bowel diseases (rs9557195). Patients of the Swiss IBD cohort study have been genotyped for the allelic status of EBI2. The investigators will test the influence of rs9557195 genoty (TT or CC allel), inflammatory activity and current treatment (infliximab vs. vedolizumab) on expression and activity of EBI2 on blood lymphocytes, mRNA expression of EBI2 and UBAC2 (located on the opposite DNA strand of EBI2) and activity of lymphocytes on a migraton assay.