Moreover, upregulation of XIAP expression has been found to result in apoptosis resistance after exposure to anticancer drugs and ionising radiation (Li et al, 2000; Asselin et al, 2001; Holcik et al, 2001; Matsumiya et al, 2001), whereas downregulation of XIAP by antisense vectors increased the apoptosis sensitivity of carcinoma cell lines (Sasaki et al, 2000; Holcik et al, 2001). This evidence concerns the gene XIAP and carcinoma.