The success of a drug used to treat those with high cholesterol has been explained by scientists in the US.
The drug, Zetia, was thought to work by preventing cells in the intestine from absorbing cholesterol, but new research suggests its benefits extend to the liver.
In both organs, the drug targeted a protein called NPC1L1 which shifts cholesterol into the body's cells.
It is this protein's action which Zetia blocks, preventing the absorption of cholesterol.
Ryan Temel, lead author of the study, said: "We know that this protein that the drug targets is expressed not only in the intestine, but is abundant in the human liver.
"The fact that Zetia works in two locations is positive because it makes it more effective as a cholesterol-lowering drug."
Liqing Yu, senior researcher, said: "These findings suggest that in humans, the drug may reduce cholesterol levels in the blood by inhibiting NPC1L1 function in both the intestine and the liver."