Genes expressions for steroid 5-α reductase type 1 (SRD5A1), 3-β-hydroxysteroid dehydrogenase type 2 (HSD3B2), and aldo-keto reductase family member C3 (AKR1C3) were measured against human prostate cancer cell lines (LNCaP, LNCaP–AR, and DU-145) for the respective androgen-synthesizing enzymes. The gene discussed is AR; the disease is prostate carcinoma.