Since the expression of cellular FADD-like interleukin-1β-converting enzyme (FLICE)-inhibitory proteins (c-FLIPL and c-FLIPS) potently controls the susceptibility of cancer cells to TRAIL-induced apoptosis, we assessed the mRNA and protein levels of c-FLIPL/S in the metastatic cells treated with or without TRAIL using quantitative real-time RT-PCR and Western blot analysis, respectively. This evidence concerns the gene CASP8 and cancer.