Every cell in your body runs on messenger RNA, or mRNA. These are short-lived instructions that tell the cell which protein to build. Moderna writes its own instructions. Inject them, and the body builds whatever protein Moderna chose. That could be a piece of a virus for a vaccine, or a cancer marker the immune system can learn to hunt. Moderna Writes Medicine Like Software This August, Moderna (MRNA -1.25%) and Merck (MRK -1.34%) reported that their personalized cancer vaccine, intismeran autogene, cut th ...