TNF and inflammatory bowel disease: Currently, the clinical therapeutic repertoire for IBD is predominantly constituted by traditional medications (including aminosalicylic acid preparations, glucocorticoids, and immunosuppressants), biological agents (such as anti-tumor necrosis factor (TNF), interleukin (IL)-12/IL-23), and emerging small-molecule drugs (such as Janus-activated kinase (JAK) inhibitors and sphingosine-1-phosphate (S1P) receptor modulators).