IL1A and irritable bowel syndrome: In a study that surveyed circulating plasma and colonic tissue levels of IL-1α, IL-1β, IL-1Ra, sIL-1RI, and sIL-1RII from IBD patients and controls, it was found that sIL-1RI served as a systemic biomarker of disease activity in CD patients, while local shedding of the functional antagonist, sIL-1RII, was associated with decreased colonic inflammation in CD, but not in UC, patients (52).