Statins inhibit endogenous cholesterol production by competitive inhibition of HMG-CoA reductase (HMGCR), the enzyme that catalyzes conversion of HMG-CoA to mevalonate, an early rate-limiting step in cholesterol synthesis. This pathway delineates genes involved in statin pharmacogenomics, including genes involved in mediating the effects of statins on plasma lipoprotein metabolism.
Sources: [PharmGKB](https://www.pharmgkb.org/pathway/PA2031) and [Wikipedia](http://en.wikipedia.org/wiki/Statin).