TNFSF10 and cancer: TRAIL on the other hand is a potent inducer of apoptosis in cancer cells in vitro (Wiley et al, 1995; Pitti et al, 1996) and in its native biological form, it exhibits antitumour activity in several xenograft studies in vivo without serious toxicity (Ashkenazi et al, 1999; Gliniak and Le, 1999; Walczak et al, 1999).