Squalene synthase is a microsomal enzyme which catalyzes the reductive dimerization of two molecules of farnesyl pyrophosphate (FPP) to form squalene (1, Figure 1). This enzyme is involved in the first committed step of the de novo cholesterol biosynthetic pathway. 1 As suggested by in vivo experiments, inhibition of squalene synthase will block cholesterol biosynthesis and thus should act to suppress elevated serum cholesterol (vide infra). ...