Another key enzyme in the mevalonate pathway, farnesyl diphosphate synthase (FDPS), is involved in the conversion of acetyl-CoA to cholesterol [41]; FDPS inhibitors, such as the bisphosphonate alendronate, reduce cholesterol synthesis and are used in the treatment of hypercholesterolemia [42, 43]. The gene discussed is FDPS; the disease is familial hypercholesterolemia.