AR and cancer: 3β hydroxysteroid dehydrogenase (3βHSD1) an AR regulated enzyme, which catalyses the formation of extragonadal androgens within the tumours from adrenal precursors thus fuelling cancer progression [94] Gain-of-function mutations in 3βHSD1 such as N367T has been linked to increased enzyme accumulation, leading to enhanced androgenic flux within the CRPC [93].