TNF (Tumor Necrosis Factor) is a cytokine belonging to the TNF superfamily, primarily including TNF-α and TNF-β. These proteins exist in both membrane-bound and soluble forms, predominantly distributed among immune cells. TNF activates signaling pathways such as NF-κB by binding to its receptors TNFR1 and TNFR2, involved in inflammatory responses, cell proliferation, differentiation, and apoptosis. The gene expression of TNF is tissue and condition-specific, with abnormal expression or mutations associated with various inflammatory and autoimmune diseases.