Indeed, tumors with low Caspase-8, or high levels of FLIP, may inherently be resistant to such therapies (reviewed in [9,50]) The biological manipulation of the expression of Caspase-8 or of those proteins that may modulate its function such as FLIP, may therefore synergize with radio- and chemotherapy to enhance tumor killing [5]. This evidence concerns the gene CASP8 and neoplasm.