We previously demonstrated that the mouse strain SPRET/Ei (S) displays an extreme and dominant resistance against TNF-induced SIRS and that this trait is linked to a locus on proximal chromosome 2 and one on distal chromosome 6, the latter containing Tnfrsf1a (Staelens et al, 2002). This evidence concerns the gene TNFRSF1A and systemic inflammatory response syndrome.