Aminoglutethimide, an inhibitor of cholesterol side-chain cleavage, 11-beta-hydroxylase (CYP11B1) and 18-hydroxylase (CYP11B2) [35], and trilostane, an inhibitor of 17-beta-hydroxysteroid dehydrogenase, 3-beta-hydroxysteroid dehydrogenase (3-beta-HSD) and 17-alpha-hydroxylase/17,20-lyase (CYP17) [36], have been used in the past but only occasionally in more recent times in the treatment of CS, because of their unsatisfactory pharmacological profile. Here, HSD3B1 is linked to Cowden syndrome 1.