Androgen biosynthesis is physiologically necessary for generating the principal stimulus for androgen receptor (AR) signaling and thus plays an essential role for development of the normal prostate, prostate cancer growth, and the development of resistance to hormonal therapies. Testosterone and dihydrotestosterone are both potent endogenous androgens that stimulate AR signaling. While the role of gonadal androgens in stimulating prostate cancer progression has been recognized for over 80 years,