Over the past decades, immunosuppressive and newly developed biological agents, including anti-tumor necrosis factor α (TNF-α) agents and small molecules such as anti-integrin agent, have been employed for the treatment of IBD, in addition to conventional therapies that involve 5-aminosalicylic acid and corticosteroids, thereby improving the treatment outcomes of IBD. The gene discussed is TNF; the disease is inflammatory bowel disease.