The antitumour activity of flavone acetic acid (FAA) against a range of transplantable murine tumours with established vasculature is well documented (Plowman et al, 1986; Smith et al, 1987; Hill et al, 1989) and appears to be related to the production of tumour necrosis factor-alpha (TNF-α), since antibodies to TNF can prevent the reduction in blood flow caused by FAA (Mahadevan et al, 1990). The gene discussed is TNF; the disease is neoplasm.