Tumor necrosis factor is a biologic response modifier. It is also labeled a cytokine because of its effect on other cells . It is normally produced by the "clean-up" cells called macrophages and, with recombinant DNA technology, can be produced in the laboratory. It has remarkable actions on the coagulation pathways but has shown few antitumor effects even at dosage levels that are quite intolerable, causing weight loss, fever and low blood pressure. A number of experimental observations, however, has meant that interest persists in studying it in combination with chemotherapy .
