It is tempting to speculate that this difference in circulating IL-7 is, in part, related to the higher rate of nosocomial infections in the severe extremity fracture group as compared to the mild/moderate injury group, given that circulating IL-7 levels are reduced in sepsis patients [59] and that administration of IL-7 can restore lymphocyte functions in the setting of sepsis [60]. This evidence concerns the gene IL7 and nosocomial infection.