Previously, steroidogenesis has been shown to promote the development of adrenocortical, endometrial and prostate cancers, all of which exhibit abundant steroidogenesis.4, 5, 6 Evidence that CYP17A1 is absolutely required for steroidogenesis in the prostate gland suggests that CYP17A1 may be a valuable therapeutic target in prostate cancer.7 In contrast, whether neural DHEA and steroidogenesis are involved in the development of brain tumors that utilize high levels of cholesterol,8 such as GBM, is unknown. This evidence concerns the gene CYP17A1 and prostate cancer.