John Sears · CC BY-SA 4.0

Gary Ruvkun discovered let-7, the second microRNA ever found and the first shown to be conserved across animal species including humans — evidence that this newly discovered layer of gene regulation, working at a scale far smaller than genes themselves, was not a one-off curiosity but a fundamental feature of biology. Building on Victor Ambros's discovery of the first microRNA, lin-4, Ruvkun worked out the mechanism by which it silences its targets. He also uncovered features of insulin-like signaling in aging and metabolism, and received the 2024 Nobel Prize in Physiology or Medicine for the microRNA work.