TNF and neoplasm: In previous work, we showed that Apo2L/TRAIL, a recombinant form of TRAIL, a tumor necrosis factor (TNF) family member which binds to the cell surface death receptors DR4 and DR5 and initiates apoptosis through the extrinsic apoptotic pathway, can effectively inhibit tumor growth in several PDX models of pancreatic cancer [14, 15].