The plasma concentrations of 11 inflammatory mediators with pro- and anti-inflammatory activity (IL-1, IL-4, IL-6, IL-8, IL-9, IL-15, eotaxin, bFGF, G-CSF, GM-CSF, and TNF-α) were higher in children with severe CAP than in children with mild pneumonia. Here, CXCL8 is linked to susceptibility to pneumonia measurement.