TNF and neoplasm: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor (TNF) family and widely expresses in a variety of tissues; due to the difference in sensitivity to TRAIL between normal cells and tumor cells, TRAIL can selectively induce apoptosis of tumor cells but almost has no killing effect on normal cells; hence, TRAIL is considered a promising antitumor agent (2–4).