4α-Carboxy-4β-methyl-cholest-8,24-dien-3β-ol is a sterol related to Zymosterol (Z701520), which is an intermediate in the biosynthesis of cholesterol (C432501). Cholesterol is a major component of all biological membranes. Zymosterol was also found to be located in the plasma membrane of cultured human fibroblasts via labeling studies.