Luke Koblan sat at his desk, staring at some data. Excited but baffled, the grad student thought, there’s no way those numbers could be right. He shared the results with his boss, Professor David Liu, and today, that data has spurred a team of scientists from the Broad Institute of MIT and Harvard (including Koblan and Liu), the National Institutes of Health, and Vanderbilt University Medical Center to achieve an almost unbelievable leap for the CRISPR gene-editing tool known as base editing, moving the technology a critical step closer to being a treatment for progeria, a deadly premature aging disease.