AR and Familial prostate cancer: Prostate cancer (PCa) is the second leading cause of cancer‐related death among men in the United States, behind only lung cancer.1 It is a disease of extensive metastases with secondary lesions commonly occurring in lymph nodes, brain, bones, and sometimes in visceral organs such as the liver and lungs.2, 3 While androgen‐deprivation therapy targeted toward androgen receptor (AR) signaling is widely used for advanced PCa, this therapeutic strategy has been marred by major clinical limitations.