Chairman of the Nobel Committee Goeran Hansson announnces winners of the Nobel Prize in medicine at a press conference on October 7, 2013 at the Karolinska Institute in Stockholm. The 2013 Nobel Prize in Physiology or Medicine went to James E. Rothman, Randy W. Schekman and Thomas C. Sudhof "for their discoveries of machinery regulating vesicle traffic, a major transport system in our cells," according to the Nobel Assembly. (Xinhua/Shi Tiancheng)