TNF and inflammatory bowel disease: Recently, biologics comprising anti-tumor necrosis factor, anti-α4β7 integrin, anti-interleukin (IL)-12, and IL-23 agents, and small-molecule drugs such as Janus kinase (JAK) inhibitors and sphingosine-1-phosphate (S1P) receptor modulators have been introduced as anti-IBD drugs, which has expanded the therapeutic landscape for IBD, especially for patients with severe IBD [6].