Drugs which can regulate levels of cholesterol in the blood may also reduce the risk of dangerous clots, say scientists.
Blood clots can result in stroke or heart attack.
Researchers, writing in the journal Blood, reduced the size and stability of blood clots in mice and said the discovery could lead to new drugs.
The British Heart Foundation said it was an exciting discovery which could result in more effective treatments.
Around 32,000 people in the UK die after developing a blood clot.
The team at the University of Reading was investigating how clots form and say they were surprised to find that protein, LXR, was involved.
LXR is already known to control levels of cholesterol and drug companies have been targetting it for new treatments.
The researchers found that drugs which affect LXR reduced the size and stability of growing clots in experiments on mice.
Professor Jon Gibbins, from the University of Reading, said: “It’s really quite exciting really, it could be quite an important discovery.”
“While blood clotting is essential to prevent bleeding, inappropriate clotting within the circulation, known as thrombosis, is the trigger for heart attacks and strokes – which kill more people in the UK each year than any other disease.
“This study paves the way for new and more effective medicines to prevent thrombosis.”
Professor Jeremy Pearson, associate medical director at the British Heart Foundation, said: “Both anti-clotting and cholesterol lowering drugs are vital in reducing the chance of a heart attack or stroke in high-risk patients, but are not always effective and don’t suit all patients because of the risk of side-effects.
“This exciting discovery shows that drugs which lower cholesterol through targeting LXR protein can also reduce harmful blood clotting – potentially opening up paths towards new, more effective treatments.”