Table 1.

Primary signaling pathways and relative drug applications of Crohn’s disease

Signaling pathway	Relative function	Targeted factor	Drug application
NF-κB	Maintenance of epithelial integrity and intestinal immune homeostasis	TNF-α	infliximab, adalimumab, and certolizumab
		IL-12/23	ustekinumab
		IκBa	corticosteroids
TGF-β/SMAD3	Immunosuppression and fibrosis	SMAD7	mongerson
JAK/STAT	Immunoregulation, anti-inflammation and epithelial barrier function	JAK	tofacitinib and filgotinib
Chemokines/integrins	Leukocytes trafficking to targeted location	α4β7 integrin	vedolizumab
		α4β7 and αEβ7 integrins	etrolizumab
		MAdCAM1	PF-00547659
Wnt	Regulation of epithelial proliferation and gut mucosal homeostasis	NA	NA

NF-κB: Nuclear factor kappa B; TGF-β: Transforming growth factor-β; JAK: Janus kinase; STAT: Signal transducer and activator of transcription; Wnt: Wingless/Int1; TNF-α: Tumor necrosis factor-α; IL: Interleukin; NA: Not available.