Increased IL-17A/IL-17F expression ratio represents the key mucosal T helper/regulatory cell-related gene signature paralleling disease activity in ulcerative colitis.

Background T helper (Th) and regulatory T (Treg) cell-related cytokines are implicated in inflammatory bowel diseases, including ulcerative colitis (UC). While these cytokines are generally upregulated in inflamed mucosae, the key cytokine profile explaining disease severity has not been determined.