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![Intracrine androgen biosynthesis and drug resistance](https://image.oaes.cc/0fc092bc-8946-4c34-b05d-db09e804581b/3734.fig.1.jpg)
Figure 1. Intracrine androgen biosynthesis. Top panel shows reactions that occur in the adrenal reticularis. Bottom panel shows the conversion of adrenal steroids into the potent androgens testosterone and 5α-DHT in human prostate. The classical or canonical pathway is shown in red; the 5α-adione pathway is shown in blue; the backdoor pathway from allopregnanlone is shown in purple; the alternative pathway from 5-androstenediol is also shown. All enzymes are listed in italics by their gene names as follows: AKR1C1, 3α(20α)-hydroxysteroid dehydrogenase; AKR1C2, type 3 3α-hydroysteroid dehydrogenase; AKR1C3, type 5 17β-hydroxysteroid dehydrogenase; CYP17A1, 17α-hydroxylase17/20 lyase; HSD3B1, type 1 3β-hydroxysteroid dehydrogenase; HSD17B2 and 17HSD17B4, type 2 and type 4 17β-hydroxysteroid dehydrogenase; HSD17B6, type 6 17β-hydroxysteroid dehydrogenase and retinol dehydrogenase; and SRD5A1/2, type 1 and type 2 steroid 5α-reductase