License to Kill Tumors: How Much Hope is Justified for Trail

In 1995, a new cytokine termed TRAIL (tumor necrosis factor - related apoptosis-inducing ligand) was discovered and demonstrated to selectively induce programmed cell death in transformed cell lines. Preclinical cytotoxicity studies in mice and nonhuman primates have produced promising results by demonstrating that TRAIL exerts potent tumoricidal activity but lacks severe toxicity towards normal tissues making it a potentially ideal candidate for cancer therapy. This article reviews aspects of our current understanding of TRAIL signaling pathways and summarizes how this knowledge is currently being translated into TRAIL-based tumor-selective therapeutic strategies