Shiv Grewal hasn't slept much in the past eight or nine years. Not since he found that in fission yeast, gene silencing depends on the machinery that carries out RNA interference (RNAi), a discovery that effectively tied together two of the hottest areas in modern cell biology. "I've never seen someone work so hard," says former postdoc Ken-ichi Noma of the Wistar Institute in Philadelphia. "I'm Japanese, and Japanese people usually try to work more than the boss. But I gave up. It was physically impossible. He was in lab by 9:00 every day and then he worked until 3:00 or 4:00 in the morning. I don't know how he did it."












