evidence: The gene Verve is editing is called PCSK9. It has a big role in maintaining LDL levels and the company says its treatment will turn the gene off by introducing a one-letter misspelling. [...] One reason Verve's base-editing technique is moving fast is that the technology is substantially similar to mRNA vaccines for covid-19. Just like the vaccines, the treatment consists of genetic instructions wrapped in a nanoparticle, which ferries everything into a cell. While the vaccine instructs cells to make a component of the SARS-CoV-2 virus, the particles in Verve's treatment carry RNA directions for a cell to assemble and aim a base-editing protein, which then modifies that cell's copy of PCSK9, introducing the tiny mistake. In experiments on monkeys, Verve found that the treatment lowered bad cholesterol by 60%. The effect has lasted more than a year in the animals and could well be permanent. The report notes that the human experiment does carry some risk. "Nanoparticles are somewhat toxic, and there have been reports of side effects, like muscle pain, in people taking other drugs to lower PCSK9," reports MIT Technology Review.