In contrast to other members of the TNF family, such as CD95L/FasL and TNF, TRAIL has been detected in a wide variety of both non-neoplastic and neoplastic cell types and tissues (Wiley et al, 1995; Pitti et al, 1996) and was found to induce programmed cell death in cancer cells, but not in most normal cells (Gura, 1997; Sheridan et al, 1997; Walczak et al, 1997; Ashkenazi et al, 1999; Dejosez et al, 2000). Here, TNF is linked to cancer.