umls-concept:C0075086 | skos:definition | MSH: The second enzyme in the committed pathway for CHOLESTEROL biosynthesis, this enzyme catalyzes the first oxygenation step in the biosynthesis of STEROLS and is thought to be a rate limiting enzyme in this pathway. Specifically, this enzyme catalyzes the conversion of SQUALENE to (S)-squalene-2,3-epoxide. | lld:umls |