Additionally, the expression of 3-hydroxy-3-methylglutaryl-CoA synthase 1 (HMGCS1), HMGCR, and 3β-hydroxysteroid-Δ24 reductase (DHCR24), which play a key role in cholesterol de novo synthesis, is reduced in GBM cells 34, indicating that the de novo synthesis pathway of cholesterol in GBM is suppressed. This evidence concerns the gene HMGCR and glioblastoma.