**3. Tumor necrosis factor-alpha (TNF-)**

The Tumour Necrosis Factor Alpha (TNF-) is a pro-inflammatory cytokine produced by monocytes/macrophages and activated by mast cells, endothelial cells, fibroblasts, neurons and glial cells during acute inflammation and it is responsible for a wide range of cell signals about cell viability, gene expression, homeostasis control and synaptic integrity.

TNF- was described for the first time by Carswell et al. in 1975 as a protein component of serum of mice stimulated with bacterial antigens, and was brought to light the ability to induce death in cancer cell lines in vitro and in vivo to destroy transplanted sarcomas. Characteristically, this cytokine was able to cause tumor cells death without compromising the viability of healthy cells. The subsequent isolation and molecular characterization of the gene have provided information on the structure and functioning of this molecule.
