Severe sepsis and septic shock are the most serious compli- cations of bacterial infections. Both gram-positive and gram- negative bacteria can trigger these extreme inflammatory re- sponses and, by so doing, cause substantial morbidity and mortality. In the United States alone, over 400 000 patients suffer from septicaemia each year, and approximately 100 000 of these patients die despite optimal intensive care and modern antimicrobial therapy. These dramatic figures have prompted intensive research to define the bacterial and host factors involved in the septic response. Scientists from...