TNF and cancer: Engelhardt et al. (1991) intravenously administered escalating doses (from 0.15 ng/kg to 5.0 ng/kg) of purified-LPS from Salmonella abortus equi to cancer patients at 2-week intervals, and observed a strong rise in TNF-α, IL-6 and granulocyte-colony-stimulating factor (G-CSF) levels in serum.