Steroids function as important components of cell membranes and many of them are signaling molecules. All steroids are manufactured in cells from the sterols lanosterol (animals and fungi) or cycloartenol (plants). Lanosterol and cycloartenol are derived from the cyclization of the triterpene squalene. gas chromatography steroids analysis https://lipidomics.creative-proteomics.com/steroids-targeted-lipidomics.htm