FIGURE 27. Steroidogenesis. Steroidogenesis: the “classic” and “backdoor” pathways for dihydrotestosterone (DHT) synthesis. See Table 7 for enzyme nomenclature. DHEA: dehydroepiandrosterone, DHP: dihydroprogesterone. Reprinted from ref. (530): Fluck CE, Meyer-Boni M, Pandey AV, Kempna P, Miller WL, Schoenle EJ, Biason-Lauber A. Why boys will be boys: two pathways of fetal testicular androgen biosynthesis are needed for male sexual differentiation. American Journal of Human Genetics 89:201-218 (2011). Copyright 2011, with permission from Elsevier. http://www.cell.com/AJHG/abstract/S0002-9297(11)00262-X (top figure), and ref. (531): Wilson JD, Shaw G, Leihy ML, Renfree MB. The marsupial model for male phenotypic development. Trends in Endocrinology and Metabolism, 13:78-83 (2002), Copyright 2002, with permission from Elsevier. http://www.sciencedirect.com/science/article/pii/S1043276001005252 (bottom figure).