A phase 1 study enrolled six patients with heterozygous familial hypercholesterolemia who were treated with experimental gene therapy using lipid nanoparticles.[5] The treatment was aimed at inactivating the PCSK9 gene in hepatocytes (liver cells) using a DNA base editing technique.[5] This method allows for precise changes in DNA without creating dangerous breaks in the genetic material, thus reducing the risk of adverse effects.[5] Preliminary results showed a reduction in LDL cholesterol levels and a favorable safety profile in patients.[5] The treatment is given as a single infusion, which could potentially replace the need for long-term use of cholesterol-lowering drugs.[3] The study represents a major advance in the treatment of hereditary high cholesterol with gene therapy.