Two studies have reported that patients with the 4G/4G genotype of the PAI-1 gene had higher plasma PAI-1 concentrations and higher risk of death than those with the 4G/5G or 5G/5G genotypes; one study involved 175 children with meningococcal disease [10], and the other included 88 adult patients with septic shock [11]. This evidence concerns the gene SERPINE1 and meningococcal infection.