Millions of Americans already take a drug to lower their LDL, or bad cholesterol, but if things go Pfizer's way, they may end up adding a pill that raises HDL, the good cholesterol that helps keep arteries clean. A study in the current New England Journal of Medicine reports that the drug torcetrapib boosted HDL levels 46%. When it was combined with the LDL-lowering drug Lipitor, the results were even more dramatic: HDL levels rose 61%, and LDL fell even more than it did with Lipitor alone. But will raising HDL levels mean lower rates of heart disease and fewer deaths? That's what Pfizer hopes to show. If it does, both the drug company and patients could be big winners.