NCIt definition : Compounds possessing the skeleton of cyclopenta[a]phenanthrene or a skeleton derived
therefrom by one or more bond scissions or ring expansions or contractions. Methyl
groups are normally present at C-10 and C-13. An alkyl side chain may also be present
at C-17. They include cholesterol, numerous hormones, precursors of certain vitamins,
bile acids, alcohols (STEROLS), and certain natural drugs and poisons.;
Alternative definition : NCI-GLOSS: Any of a group of lipids (fats) that have a certain chemical structure.
Steroids occur naturally in plants and animals or they may be made in the laboratory.
Examples of steroids include sex hormones, cholesterol, bile acids, and some drugs.;