They further demonstrated that SIRT7 expression is positively correlated with AR signaling in both prostate cancer tissues and cells (LNCaP and 22Rv1) and that SIRT7 knockdown upregulates SMAD4, a tumor suppressor protein [129], which interacts with AR to control its signaling in prostate cancer [130]. This evidence concerns the gene SIRT7 and Familial prostate cancer.