TNF-alpha (Tumor Necrosis Factor-alpha) is a key member of the TNF family, an inflammatory cytokine primarily produced by macrophages. It exists in both soluble and membrane-bound forms, predominantly expressed in immune cells. TNF-alpha activates multiple signaling pathways, such as NF-κB and MAPK, by binding to TNFR1 and TNFR2 receptors, involved in regulating inflammation, immune responses, and apoptosis. The gene expression of TNF-alpha is tightly regulated, with mutations or overexpression associated with the development of various inflammatory and autoimmune diseases.