CXCL8 and isolated hyperferritinemia: Mortality was associated with Glasgow Coma Scale Score < 12, decreased TNF and IL-2Ra levels, and increased MCP3 levels in PedSep-A; increased IL-6, IL-8, and MCP1/CCL2 levels in PedSep-B; high ferritin, lymphopenia, lower temperature, higher blood pressure, and increased IL-8 levels in PedSep-C; and hyperferritinemia, chronic illness, increased MIP-1α, IL-8, and IL-10 levels, and decreased IL-18 and sFASL levels in PedSep-D (Fig. 4, Additional file 1: Tables S9–S11, Additional file 1: Fig. S12).