Researchers delivered an mRNA‑based epigenetic editor targeting PCSK9 to nonhuman primate livers and reported durable reductions in PCSK9 expression and LDL cholesterol for nearly a year after a single dose, according to a Nature Biotechnology paper. The approach, termed Epi‑Reg in the study, uses transient mRNA delivery to achieve durable, reversible epigenetic repression without permanent DNA edits in preclinical models. Authors highlighted safety and reversibility as advantages over permanent genome editing and compared the durability favorably to existing therapies. The work positions epigenetic editing as a translational route for chronic cardiometabolic conditions, but regulators and developers will require extended toxicology and durability data before clinical trials.