Finally, involvement of caspase-8 in CD40L-induced apoptosis of NB cells was demonstrated by Western blot experiments in which IFN-γ gene-transfected ACN cells were cultured with rCD40L or medium in the presence or absence of Z-LETD-FMK for 15 or 24 h (Figure 5C). This evidence concerns the gene IFNG and neuroblastoma.