TMPRSS2 and Familial prostate cancer: Since the prostate cancer-prevalent T:E fusion gene is formed by the fusion with the androgen-responsive regulatory region of the AR-targeted TMPRSS2 gene, it is generally viewed that T:E fusion is primarily regulated by AR and its aberrant expression in androgen-dependent prostate cancer is mainly attributed to the activated AR signaling, and AR targeting by androgen ablation or hormone therapy could help to suppress its aberrant overexpression in prostate cancer.