PathwayStep1626 PathwayStep1617 PathwayStep1658 PathwayStep1641 PathwayStep1645 PathwayStep1634 Glucocorticoid biosynthesis Mineralocorticoid biosynthesis Vitamin D (calciferol) metabolism Androgen biosynthesis Estrogen biosynthesis Pregnenolone biosynthesis Steroid hormones Active steroid hormones are produced from the precursor cholesterol.The steps involved in the biosynthesis of the adrenal steroid hormones, corticosterone, cortisol, and aldosterone; and the gonadal steroid hormones, progesterone, estradiol, and testosterone are annotated here. The enzymes that catalyze these reactions fall into two major classes of proteins: the cytochrome P450 heme-containing proteins and the hydroxysteroid dehydrogenases. Authored: Jassal, B, 2008-10-01 13:18:42 Edited: Jassal, B, 2008-11-17 10:09:58 Pubmed15583024 Reactome Database ID Release 43209943 Reactome, http://www.reactome.org ReactomeREACT_15493 Reviewed: D'Eustachio, P, 2008-11-29 15:53:45