To determine the relative levels of expression of let-7c in PCa cells, we isolated total RNAs from LNCaP (androgen-dependent, AR-positive), PC-3, DU145 (castration-resistant, AR-negative) cells as well as LNCaP-S17 cells expressing IL-6 [30] and LN-IL6+ cells chronically treated with IL-6 [31]. The gene discussed is IL6; the disease is posterior cortical atrophy.