Statin drugs inhibit HMG-CoA reductase enzyme and prevent conversion of Mevalonate to Cholesterol and thereby reduce the cholesterol level in our body but the pathway to conversion of HMG-CoA to Cholesterol involves a lot of different steps and different enzymes, so how do we narrow it down to HMG-CoA reductase only? Why not think of other enzymes to inhibit? How do they figure out which step to inhibit? Is there any reasoning to it?