The Th1 subset, differentiated by IL-12 stimulation, expression of transcription factor T-bet, and release of interferon (IFN)-γ, IL-6, and IL-12 is predominant in Crohn’s disease (CD), whereas Th2, influenced by IL-4 or IL-5, is dependent on GATA binding protein 3 (GATA3) and its secreted cytokines IL-4, IL-5, and IL-13 are activated in UC. The gene discussed is GATA3; the disease is Crohn disease.