In septic patients, even low plasma levels of meningococcal LOS (<1 ng/mL) are associated with meningococcal septic shock and death [9, 31] and LOS is a potent inducer of proinflammatory cytokines, including IL-1β, TNF, IL-6, and CXCL8, in human and murine macrophages [8, 10, 31] as well as IL-1β in human blood ex vivo [30]. This evidence concerns the gene IL1B and septic shock.