TNF-alpha is a clinically important cytokine with strong pro-inflammatory activities. TNF-alpha is secreted by a variety of immune and non-immune cells including adipocytes, activated monocytes, macrophages, B cells, T cells and fibroblasts. TNF-alpha signals through two receptors, TNFR1 and TNFR2. TNF-alpha has strong cytolytic activities against a wide variety of tumor cells and is critically important in combat against bacterial infections. The inflammatory effects of TNF-alpha are also deleterious in causation of septic shock, and autoimmune diseases including rheumatoid arthritis, inflammation, and diabetes.