Abstract Tumor necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL) is a member of the
TNF superfamily of cytokines that can induce cell death through engagement of cognate death receptors. Unlike other death receptor ligands, it selectively kills tumor cells while sparing normal cells.
Preclinical studies in non-human primates have generated much enthusiasm regarding its therapeutic potential. However, many
human cancer cell lines exhibit significant resistance to TRAIL-induced apoptosis, and the molecular mechanisms underling this are controversial. Possible explanations are typically cell-type dependent, but include alterations of receptor expression, enhancement of