Derivados del colesterol
<a href="//commons.wikimedia.org/wiki/User:Alejandro_Porto" title="User:Alejandro Porto">Alejandro Porto</a>
CC BY-SA 3.0
<a href="//commons.wikimedia.org/wiki/File:Estradiol_3D_ball.png" title="File:Estradiol 3D ball.png">File:Estradiol 3D ball.png</a>, <a href="//commons.wikimedia.org/wiki/File:Progesterone-3D-balls.png" title="File:Progesterone-3D-balls.png">File:Progesterone-3D-balls.png</a>, <a href="//commons.wikimedia.org/wiki/File:Corticosterone-3D-balls.png" title="File:Corticosterone-3D-balls.png">File:Corticosterone-3D-balls.png</a> y  <a href="//commons.wikimedia.org/wiki/File:Cholecalciferol-vitamin-D3-from-xtal-3D-balls.png" title="File:Cholecalciferol-vitamin-D3-from-xtal-3D-balls.png">File:Cholecalciferol-vitamin-D3-from-xtal-3D-balls.png</a>, de <a href="//commons.wikimedia.org/wiki/User:Jynto" title="User:Jynto">Jynto</a> y <a href="//commons.wikimedia.org/wiki/User:Benjah-bmm27" title="User:Benjah-bmm27">Ben Mills</a>