Early studies reported reduced IL-13 concentrations in the inflamed mucosa of patients with ulcerative colitis (UC) compared with active Crohn’s disease (CD) and healthy controls (34), and more recently this has been reinforced by data showing similar levels of mucosal IL-13 mRNA and IL-13 protein production in active UC, inactive UC, and healthy controls (35). The gene discussed is IL13; the disease is ulcerative colitis.