Tumor Necrosis Factor-α, Human, Recombinant (rhTNF-α), is a pleiotropic cytokine produced predominantly by activated monocytes/macrophages. Biological effects of this molecule include induction of apoptosis, cytolysis or cytostasis of tumor cells, activation of polymorphonuclear leukocytes, antiviral activity and induction of IL-1 or colony-stimulating factor expression. rhTNF-α is a 17kDa protein containing 157 amino acid residues that is produced from a recombinant DNA expressed in E. coli.