AR and Familial prostate cancer: Prostate Cancer Stem Cell-like population (PCSCs) with enhanced clonogenic, tumor-initiating and metastatic capacities are not only enriched for CD44 expression, but may also harbor low levels of androgen-dependent AR target gene expression such as PSA due to their ability to generate a mixed population of AR positive and AR low or negative cells in castration resistant tumors9,14–16, suggesting that this CD44+PSA−/lo subpopulation employs androgen-independent signaling mechanisms for survival17,18.