Luxembourg-born Frenchman Jules Hoffmann, one of the three scientists who won the Nobel Medicine Prize for work on the immune system, gestures as he talks during an interview in Shanghai on October 4, 2011. Hoffmann's win was hailed by French President Nicolas Sarkozy, who described it as "an honour" for all of France. AFP PHOTO

Luxembourg-born Frenchman Jules Hoffmann, one of the three scientists who won the Nobel Medicine Prize for work on the immune system, poses during an interview in Shanghai on October 4, 2011. Hoffmann's win was hailed by French President Nicolas Sarkozy, who described it as "an honour" for all of France. AFP PHOTO

Luxembourg-born Frenchman Jules Hoffmann, one of the three scientists who won the Nobel Medicine Prize for work on the immune system, poses during an interview in Shanghai on October 4, 2011. Hoffmann's win was hailed by French President Nicolas Sarkozy, who described it as "an honour" for all of France. AFP PHOTO

Luxembourg-born Frenchman Jules Hoffmann, one of the three scientists who won the Nobel Medicine Prize for work on the immune system, poses during an interview in Shanghai on October 4, 2011. Hoffmann's win was hailed by French President Nicolas Sarkozy, who described it as "an honour" for all of France. AFP PHOTO

Luxembourg-born Frenchman Jules Hoffmann, one of the three scientists who won the Nobel Medicine Prize for work on the immune system, gestures as he talks during an interview in Shanghai on October 4, 2011. Hoffmann's win was hailed by French President Nicolas Sarkozy, who described it as "an honour" for all of France. AFP PHOTO

The microscope that Ralph Steinman used in the early 70's to make his discovery about dendritic cells is displayed in his lab in New York, Monday, Oct. 3, 2011. Steinman, a cell biologist, was awarded the Nobel Prize in medicine on Monday for his discoveries about the immune system, but hours later his university said that he had been dead for three days. The Nobel committee had been unaware of Canadian-born Ralph Steinman's death. (AP Photo/Seth Wenig)

Nobel prize winner Ralph Steinman's family, from left to right, daughter Lesley Steinman, son Adam Steinman, wife Claudia Steinman and daughter Alexis Steinman, speaks to the media after a ceremony honoring him at Rockefeller University in New York, Monday, Oct. 3, 2011. Ralph Steinman, a cell biologist, was awarded the Nobel Prize in medicine on Monday for his discoveries about the immune system but hours later his university said that he had been dead for three days. The Nobel committee had been unaware of Canadian-born Ralph Steinman's death. (AP Photo/Seth Wenig)

Family members of Nobel prize winner Ralph Steinman walk in front of a picture of Steinman during a ceremony honoring him at Rockefeller University in New York, Monday, Oct. 3, 2011. From left to right are daughter Lesley Steinman, wife Claudia Steinman and son Adam Steinman. Canadian-born Ralph Steinman, a cell biologist, was awarded the Nobel Prize in medicine on Monday for his discoveries about the immune system, but hours later his university said that he had died three days earlier. The Nobel committee had been unaware of his death. (AP Photo/Seth Wenig)

--RESTRICTED TO EDITORIAL USE MANDATORY CREDIT "AFP PHOTO / CNRS DIDIERS PASCAL" NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS - RESTRICTED TO SUBSCRIPTION USE - NO ARCHIVES -- An undated photo released by the Centre national de Recherche Scientifique (CNRS) shows Luxembourg born Frenchman Jules Hoffmann who was awarded the 2011 Nobel Medicine Prize with Bruce Beutler of the US and Ralph Steinman of Canada, the Nobel jury said on October 3, 2011. "This year's Nobel laureates have revolutionised our understanding of the immune system by discovering key principles for its activation," the jury said in a statement. AFP PHOTO/CNRS DIDIERS PASCAL

--RESTRICTED TO EDITORIAL USE MANDATORY CREDIT "AFP PHOTO / CNRS DIDIERS PASCAL" NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS - RESTRICTED TO SUBSCRIPTION USE - NO ARCHIVES -- An undated photo released by the Centre national de Recherche Scientifique (CNRS) shows Luxembourg born Frenchman Jules Hoffmann who was awarded the 2011 Nobel Medicine Prize with Bruce Beutler of the US and Ralph Steinman of Canada, the Nobel jury said on October 3, 2011. "This year's Nobel laureates have revolutionised our understanding of the immune system by discovering key principles for its activation," the jury said in a statement. AFP PHOTO/CNRS DIDIERS PASCAL

In this undated photo provided by The Scripps Research Institute, Bruce A. Beutler of the Scripps Research Institute in La Jolla, Calif., poses for a photograph. The Nobel committee says American Beutler and Luxembourg-born scientist Jules Hoffmann have shared the 2011 Nobel Prize in medicine with Canadian-born Ralph Steinman on Monday, Oct. 3, 2011. Beutler and Hoffmann were cited "for their discoveries concerning the activation of innate immunity." (AP Photo/Scripps Research Institute)

FILE - This is a Tuesday, Oct. 5, 2010 file photo of Professor Andre Geim, left, and Dr Konstantin Novoselov are seen outside Manchester University, Manchester, England. The scientists won the 2010 Nobel Prize for Physics. (AP Photo/Jon Super, File)

FILE - In this April 24, 2009 photo, Dr. Ralph Steinman of Rockefeller University speaks during a news conference in Albany, N.Y., Friday, April 24, 2009. The Nobel committee says American Bruce Beutler and Luxembourg-born scientist Jules Hoffmann have shared the 2011 Nobel Prize in medicine with Canadian-born Ralph Steinman on Monday, Oct. 3, 2011. Beutler and Hoffmann were cited "for their discoveries concerning the activation of innate immunity." Steinman was honored for "his discovery of the dendritic cell and its role in adaptive immunity." (AP Photo/Mike Groll)

FILE - In this April 24, 2009 photo, Dr. Bruce Beutler of the Scripps Research Institute in La Jolla, Calif., speaks during a news conference in Albany, N.Y., The Nobel committee says American Bruce Beutler and Luxembourg-born scientist Jules Hoffmann have shared the 2011 Nobel Prize in medicine with Canadian-born Ralph Steinman on Monday, Oct. 3, 2011. Beutler and Hoffmann were cited "for their discoveries concerning the activation of innate immunity." (AP Photo/Mike Groll)

FILE - In this April 24, 2009 photo, Dr. Ralph Steinman of Rockefeller University speaks during a news conference in Albany, N.Y., Friday, April 24, 2009. The Nobel committee says American Bruce Beutler and Luxembourg-born scientist Jules Hoffmann have shared the 2011 Nobel Prize in medicine with Canadian-born Ralph Steinman on Monday, Oct. 3, 2011. Beutler and Hoffman were cited "for their discoveries concerning the activation of innate immunity." Steinman was honored for "his discovery of the dendritic cell and its role in adaptive immunity." (AP Photo/Mike Groll)

Canadian Ralph M. Steinman is seen in this undated handout image courtesy of Rockefeller University in New York. Steinman, Bruce Beutler of the United States, Jules Hoffmann of Luxembourg won the 2011 Nobel Medicine Prize on October 3, 2011 for their work on the immune system, the Nobel jury said. AFP PHOTO/ HO / Rockefeller University = RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / ROCKEFELLER UNIVERSITY " - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS = NO ARCHIVES =

Canadian Ralph M. Steinman is seen in this undated handout image courtesy of Rockefeller University in New York. Steinman, Bruce Beutler of the United States, Jules Hoffmann of Luxembourg won the 2011 Nobel Medicine Prize on October 3, 2011 for their work on the immune system, the Nobel jury said. AFP PHOTO/ HO / Rockefeller University = RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / ROCKEFELLER UNIVERSITY " - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS = NO ARCHIVES =

Canadian Ralph M. Steinman is seen in this undated handout image courtesy of Rockefeller University in New York. Steinman, Bruce Beutler of the United States, Jules Hoffmann of Luxembourg won the 2011 Nobel Medicine Prize on October 3, 2011 for their work on the immune system, the Nobel jury said. AFP PHOTO/ HO / Rockefeller University = RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / ROCKEFELLER UNIVERSITY " - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS = NO ARCHIVES =

Dr. Bruce A. Beutler, chairman of the Department of Genetics at Scripps Research Institute in La Jolla, California is seen in this undated handout image courtesy of Scripps Research Institute. Canadian Ralph Steinman, Beutler of the United States, Jules Hoffmann of Luxembourg won the 2011 Nobel Medicine Prize on October 3, 2011 for their work on the immune system, the Nobel jury said. AFP PHOTO/ HO / SCRIPPS RESEARCH INSTITUTE = RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / SCRIPPS RESEARCH INSTITUTE " - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS = NO ARCHIVES =