Intratumoral administration of aminoglutethimide (21), which inhibits synthesis of pregnenolone and estrogens (66), or metyrapone (20), which inhibits CYP11A1 and 11β-HSD1 production of corticosterone (29, 55), has been used to reduce tumor growth in vivo. The gene discussed is CYP11A1; the disease is neoplasm.