Torcetrabib blocks the enzyme CETP that ferries cholesterol from HDL to LDL, and triglycerides from LDL back to HDL. Block the enzyme, and HDL doesn't "leak" its cholesterol and can carry it back to the liver, for "processing", or whatever. HDL cholesterol goes up a lot when you take torcetrabip.

But there are some people who have congenitally defective CETP, and they have very high HDL. Unfortunately for them their heart disease rates are no better than anyone else's. There's something special about native HDL other than how much cholesterol it's carrying.