he Nobel Prize in medicine was awarded to Victor Ambros and Gary Ruvkun for the discovery of microRNA, tiny molecules that help control how genes are expressed. Their findings unlocked new areas of research into the roles these molecules play in human health. Researchers are exploring microRNA treatments for cancer, hepatitis and heart disease. Ambros and Ruvkun were postdoctoral fellows in the 1980s in the laboratory of biologist Robert Horvitz, who won the Nobel Prize in 2002 for his research in gene regulation. In Horvitz’s lab, they studied the roundworm C. elegans to better understand the role genes play in...