TNF-related apoptosis-inducing ligand (TRAIL), a member of the TNF superfamily, has previously been shown to be a promising anti-cancer therapeutic agent (Wiley et al. 1995; Pitti et al. 1996) for its ability to induce apoptosis in a variety of tumour cells, without affecting normal cells (Ashkenazi et al. 1999; Lawrence et al. 2001). The gene discussed is TNFSF10; the disease is neoplasm.