Figure 1.

Schematic diagram of cholesterol anabolism divided in a branching process that starts with mevalonate synthesis and includes the rate limiting enzyme, HMGCR. Subsequent to the mevalonate pathway, isoprenoid side-products and squalene are generated. The post squalene portion commits to sterol synthesis and leads to lanosterol production. The pathway then takes two routes: cholesterol synthesis I and II. Both pathways result in the production of cholesterol but differ in the specific enzymatic steps and intermediate metabolites of the pathways. Cholesterol synthesis pathway I is further subdivided into cholesterol synthesis III that is most prominent during early brain development.