Zymostenol is a late-stage precursor in the biosynthesis of cholesterol.{48201} It is an agonist of retinoic acid receptor-related orphan receptor ? (ROR?) with an EC50 value of 1 µM in a ROR? coactivator recruitment assay in the presence of ursolic acid (Item No. 10072). It increases the number of myelin basic protein-positive oligodendrocytes generated from oligodendrocyte precursor cells in vitro.{48202} Zymostenol accumulates in cells following administration of microsomal antiestrogen-binding site (AEBS) ligands, such as tamoxifen (Item No. 13258), which are associated with cell differentiation and a protective type of autophagy.{48203,48204} When used alone at a concentration of 20 µM, zymostenol halts the cell cycle at the G0/G1 phase and increases the levels of free sterols, esterified sterols, and triacylglycerols in MCF-7 cells.{48203}