After sub-lethal cecal ligation and puncture (CLP) as in vivo model for acute poly-microbial septic peritonitis, properdin deficient −/− mice showed distinctly decreased survival; in the first 7 days of the observation period, 14 of 16 wild-type mice survived, whereas only 6 of 16 properdin deficient mice survived [29]. The gene discussed is CFP; the disease is peritonitis.