Abstract: The present invention relates to a novel human gene encoding a polypeptide which is a member of the TNF receptor family, and has now been found to bind TRAIL. More specifically, an isolated nucleic acid molecule is provided encoding a human polypeptide named tumor necrosis factor receptor-5, sometimes referred to as “TNFR-5” or “TR5”, and now referred to hereinafter as “TRAIL receptor without intracellular domain” or “TRID.” TRID polypeptides are also provided, as are vectors, host cells, and recombinant methods for producing the same. The invention further relates to screening methods for identifying agonists or antagonists of TRAIL polypeptide activity. Also provided are diagnostic and therapeutic methods utilizing such compositions.