In moderate to severe CD, the guidelines recommend corticosteroids to induce remission and the use of biologics, including anti-TNF agents (e.g., infliximab, adalimumab, and certolizumab pegol), integrin inhibitors (e.g., vedolizumab), and IL-12/23 inhibitors (e.g., ustekinumab) for both induction and maintenance therapy. The gene discussed is TNF; the disease is Cowden disease.