In conclusion, our results have demonstrated that treatment with simvastatin induces apoptosis in prostate cancer cells in vitro and tumor xenograft in vivo via simultaneous modulation of mitochondria-associated intrinsic pathway that comprises Bcl-2, Bcl-xL and caspases 9 and 3 as well as Fas-L and TNF-dependent extrinsic death receptor pathway involving caspase-8. This evidence concerns the gene CASP9 and neoplasm.