To assess whether butyrate induces CD4+ T cell IL-22 production in IBD patients for translational potential, we treated peripheral blood CD4+ T cells, isolated from healthy volunteers, and patients with active Crohn’s disease (CD) and ulcerative colitis (UC), with anti-CD3 mAb and anti-CD28 mAb with or without butyrate. The gene discussed is CD28; the disease is Crohn disease.