The discovery of TRAIL (TNF Related Apoptosis Inducing Ligand), also referred to as Apo-2, is in an era of intense research because TRAIL induces many cancer cells to undergo programmed cell death (apoptosis), while having no effect on normal cells. This important protein deserves extensive review at a formative time in the development of our knowledge concerning its mechanism of action and the ways in which it can be used as a cancer chemotherapeutic agent. Consequently, this volume reviews the current status of research on TRAIL. Selected Contents include: crystal structure of RANK Ligand involved in bone metabolism; promoter of TRAIL-R2 Gene; Monoclonal Antibodies against TRAIL; modulation of TRAIL signaling complex; TRAIL in the airways; FLIP Protein and TRAIL-Induced Apoptosis; TRAIL and Ceramide; TRAIL and viral Infection; and TRAIL and Malignant Glioma.