 Patients with ulcerative colitis who do not respond to medications are still treated with colectomy (= removal of the colon).However, basic science research showed that many cytokines were elevated in both Crohn's disease and ulcerative colitis.Crohn's disease cytokines are of the type 1 ("Th1") cytokines, which include TNF-α, interleukin-2, and interferon γ. Ulcerative colitis was less conclusively linked to the production of "Th2" cytokines.