The apoptosis induced by ATR II in prostate cancer was also found to be mediated through mitochondrial intrinsic pathways, mainly through mediating an overexpression of tumor suppressor p53 that drive an unbalance on the complex Bcl-2/BAX consequently promote the release of cytochrome c, and therefore by cascades activation of caspase9/3. The gene discussed is TP53; the disease is prostate cancer.