Researchers delivered an mRNA‑based epigenetic editor targeting PCSK9 that produced durable LDL cholesterol reductions in nonhuman primates for nearly a year after a single dose. The team reported these findings in Nature Biotechnology, positioning epigenetic editing—reversible modification of gene expression without changing DNA sequence—as an alternative to permanent genome edits or repeat dosing biologics. The approach (Epi‑Reg) uses mRNA to deliver an editing complex to the liver; investigators highlight reversible and potentially safer modulation compared with nuclease‑based knockout strategies. For clinicians: PCSK9 reduction is a validated pathway to lower coronary heart disease risk, and this work shows proof‑of‑concept for long‑acting, nonpermanent gene‑modulation therapeutics.