In our own study, the median concentration of PCT and CRP was higher in the group of patients with sepsis compared to those with SIRS (1.15 ng/ml and 34.4 mg/l vs. 0.8 ng/ml and 28.7 mg/l, respectively), whereas IL-6 concentration was higher in the group of SIRS patients compared to children with sepsis (32.6 pg/ml vs. 26.4 pg/ml). This evidence concerns the gene CRP and systemic inflammatory response syndrome.