Ohio State's Carlo Croce takes center stage in this Smithsonian Magazine article that also tells the story of how microRNAs were uncovered. In the early 1990s, Croce had been looking for a gene for chronic lymphocytic leukemia, but didn't come up with anything. Then, though, Victor Ambros and Gary Ruvkun were studying different C. elegans mutants in which they found those mutations were in genes that coded for microRNAs.