“…It has diverse biological effects in other experimental systems including killing of tumour cells in vitro (Old, 1985), inhibition of the activity of lipoprotein lipase (cachectin activity) (Beutler & Cerami, 1987); mediation of some of the lethal effects of endotoxin in animals (Beutler et al, 1985), stimulation of granulocytes and fibroblasts (Old, 1985;Beutler & Cerami, 1987;Vilcek et al, 1986), damage to endothelial cells (Sato et al, 1986), bone resorption (Bertolini et al, 1986), antiviral activity (Mestan et al, 1986;Wong & Goeddel, 1986) and cytotoxic effects against malarial parasites (Taverne et al, 1981(Taverne et al, ,1984. Raised serum TNF levels are associated with some infections in man (Scuderi et al, 1986;Waage et al, 1987). Macrophageproduced TNF (which we have studied) is sometimes referred to as TNF alph-a to distinguish it from lymphocytotoxin, a closely related lymphocyte-product which may be called TNF beta (Pennica et al, 1984).…”