A protein called PCSK9 helps break down the liver's 'LDL cholesterol cleaners,' so more bad cholesterol stays in your blood, raising heart disease risk. People with certain PCSK9 gene changes either have very high or very low cholesterol levels.

People born with a certain gene change that breaks the PCSK9 gene tend to have much lower 'bad' cholesterol their whole lives and are far less likely to get heart disease — so scientists think blocking this gene with medicine might help protect others' hearts too.

People with certain genetic changes that turn down a protein called PCSK9 tend to have lower 'bad' cholesterol their whole lives and are much less likely to get heart disease.

A protein called PCSK9 causes the liver to break down fewer 'bad' cholesterol carriers, which means more of it stays in your blood.

Some people of African descent have genetic changes in a gene called PCSK9 that seem to cut bad cholesterol levels by almost half—this might help explain why they have lower heart disease risk.

People who naturally have a broken PCSK9 gene — which keeps their bad cholesterol low their whole life — are much less likely to get heart disease, and this seems to be true for people of many different backgrounds.